diff --git a/RabbitGRBL/src/Limits.cpp b/RabbitGRBL/src/Limits.cpp
index c2279bd..46d92f3 100644
--- a/RabbitGRBL/src/Limits.cpp
+++ b/RabbitGRBL/src/Limits.cpp
@@ -32,6 +32,12 @@ uint8_t n_homing_locate_cycle = NHomingLocateCycle;
 
 xQueueHandle limit_sw_queue; // used by limit switch debouncing
 
+// Tracks whether limit switch ISRs are currently attached.
+// Guards detachInterrupt() calls so they are never issued before
+// attachInterrupt() has been called (ESP32 Arduino 3.x requires the GPIO ISR
+// service to be installed before gpio_isr_handler_remove() can be called).
+static bool limits_isr_attached = false;
+
 // Homing axis search distance multiplier. Computed by this value times the cycle travel.
 #ifndef HOMING_AXIS_SEARCH_SCALAR
 #define HOMING_AXIS_SEARCH_SCALAR 1.1 // Must be > 1 to ensure limit switch will be engaged.
@@ -329,20 +335,21 @@ void limits_init()
                 if (hard_limits->get())
                 {
                     attachInterrupt(pin, isr_limit_switches, CHANGE);
+                    limits_isr_attached = true;
                 }
-                else
+                else if (limits_isr_attached)
                 {
                     detachInterrupt(pin);
                 }
-
-                /*if (limit_sw_queue == NULL)
-                {
-                    MessageSender::SendMessage(EMessageLevel::Info, "%s limit switch on pin %s", reportAxisNameMsg(axis, gang_index), pinName(pin).c_str());
-                }*/
             }
         }
     }
 
+    if (!hard_limits->get())
+    {
+        limits_isr_attached = false;
+    }
+
     // setup task used for debouncing
     if (limit_sw_queue == NULL)
     {
@@ -359,6 +366,10 @@ void limits_init()
 // Disables hard limits.
 void limits_disable()
 {
+    if (!limits_isr_attached)
+    {
+        return;
+    }
     auto n_axis = number_axis->get();
     for (int axis = 0; axis < n_axis; axis++)
     {
@@ -371,6 +382,7 @@ void limits_disable()
             }
         }
     }
+    limits_isr_attached = false;
 }
 
 // Returns limit state as a bit-wise uint8 variable. Each bit indicates an axis limit, where
diff --git a/RabbitGRBL/src/Motors/MotorsByType/Stepper_RMT.cpp b/RabbitGRBL/src/Motors/MotorsByType/Stepper_RMT.cpp
index 4700f94..7ee0670 100644
--- a/RabbitGRBL/src/Motors/MotorsByType/Stepper_RMT.cpp
+++ b/RabbitGRBL/src/Motors/MotorsByType/Stepper_RMT.cpp
@@ -21,6 +21,7 @@
 */
 
 #include "Stepper_RMT.h"
+#include "soc/rmt_struct.h"
 
 Stepper_RMT::Stepper_RMT(uint8_t axis_index, uint8_t step_pin, uint8_t dir_pin, uint8_t disable_pin)
     : Motor(axis_index), _step_pin(step_pin), _dir_pin(dir_pin), _disable_pin(disable_pin)
@@ -114,13 +115,14 @@ rmt_channel_t Stepper_RMT::get_next_RMT_chan_num()
 
 void Stepper_RMT::Step()
 {
-    // Use official ESP-IDF API instead of direct register access.
-    // rmt_tx_start(channel, true) resets the memory read pointer (mem_rd_rst)
-    // and starts transmission — equivalent to the previous low-level register writes:
-    //   RMT.conf_ch[_rmt_chan_num].conf1.mem_rd_rst = 1;
-    //   RMT.conf_ch[_rmt_chan_num].conf1.tx_start = 1;
-    // but safe, portable, and compatible across ESP-IDF versions.
-    rmt_tx_start(_rmt_chan_num, true);
+    // Direct ISR-safe register writes: reset the memory read pointer, then start TX.
+    // rmt_tx_start() is not reliably ISR-safe in ESP32 Arduino 3.x (ESP-IDF 5.x) because
+    // it acquires internal driver state and can silently fail, causing missed step pulses.
+    // These three writes are exactly what rmt_ll_tx_reset_pointer() + rmt_ll_tx_enable()
+    // (the internals of rmt_tx_start) do, and are always safe to call from an ISR.
+    RMT.conf_ch[_rmt_chan_num].conf1.mem_rd_rst = 1; // reset memory read pointer
+    RMT.conf_ch[_rmt_chan_num].conf1.mem_rd_rst = 0; // clear reset before starting
+    RMT.conf_ch[_rmt_chan_num].conf1.tx_start = 1;   // start transmission
 }
 
 void Stepper_RMT::Unstep()
diff --git a/RabbitGRBL/src/Serial.cpp b/RabbitGRBL/src/Serial.cpp
index ad972e7..5efe271 100644
--- a/RabbitGRBL/src/Serial.cpp
+++ b/RabbitGRBL/src/Serial.cpp
@@ -95,9 +95,9 @@ void clientCheckTask(void *pvParameters)
             }
             else
             {
-                vTaskEnterCritical(&myMutex);
+                vPortEnterCritical(&myMutex);
                 client_buffer.write(data);
-                vTaskExitCritical(&myMutex);
+                vPortExitCritical(&myMutex);
             }
         } // while something available
 
@@ -109,9 +109,9 @@ void clientCheckTask(void *pvParameters)
 int client_read()
 {
     // vPortEnterCritical(&myMutex);
-    vTaskEnterCritical(&myMutex);
+    vPortEnterCritical(&myMutex);
     int data = client_buffer.read();
-    vTaskExitCritical(&myMutex);
+    vPortExitCritical(&myMutex);
     // vPortExitCritical(&myMutex);
     return data;
 }
diff --git a/RabbitGRBL/src/Spindles/Spindle_PWM.cpp b/RabbitGRBL/src/Spindles/Spindle_PWM.cpp
index b204cec..41975ac 100644
--- a/RabbitGRBL/src/Spindles/Spindle_PWM.cpp
+++ b/RabbitGRBL/src/Spindles/Spindle_PWM.cpp
@@ -101,12 +101,10 @@ namespace Spindles
 
         fInvertPWM = invert;
 
-        // Setup the PWM channel
-        ledcSetup(fPWMChannelNumber, (double)fPWMFrequency, fPWMPrecision);
+        // Setup the PWM channel and attach it to the output pin
+        ledcAttachChannel(fOutputPin, (double)fPWMFrequency, fPWMPrecision, fPWMChannelNumber);
 
-        // Attach the PWM to the output pin
         pinMode(fOutputPin, OUTPUT);
-        ledcAttachPin(fOutputPin, fPWMChannelNumber);
     }
 
     void PWM::Stop()
diff --git a/RabbitGRBL/src/Stepper.cpp b/RabbitGRBL/src/Stepper.cpp
index e106a7e..89d08a1 100644
--- a/RabbitGRBL/src/Stepper.cpp
+++ b/RabbitGRBL/src/Stepper.cpp
@@ -198,16 +198,17 @@ void IRAM_ATTR onStepperDriverTimer(void *para)
 {
     // Timer ISR, normally takes a step.
     //
-    // When handling an interrupt within an interrupt serivce routine (ISR), the interrupt status bit
+    // When handling an interrupt within an interrupt service routine (ISR), the interrupt status bit
     // needs to be explicitly cleared.
-    TIMERG0.int_clr_timers.t0 = 1;
+    // Clear the interrupt status bit using the ISR-safe driver API.
+    timer_group_clr_intr_status_in_isr(STEP_TIMER_GROUP, STEP_TIMER_INDEX);
 
     bool expected = false;
     if (busy.compare_exchange_strong(expected, true))
     {
         stepper_pulse_func();
 
-        TIMERG0.hw_timer[STEP_TIMER_INDEX].config.alarm_en = TIMER_ALARM_EN;
+        timer_group_enable_alarm_in_isr(STEP_TIMER_GROUP, STEP_TIMER_INDEX);
 
         busy.store(false);
     }
@@ -1079,7 +1080,7 @@ void IRAM_ATTR Stepper_Timer_Start()
 
     timer_set_counter_value(STEP_TIMER_GROUP, STEP_TIMER_INDEX, 0x00000000ULL);
     timer_start(STEP_TIMER_GROUP, STEP_TIMER_INDEX);
-    TIMERG0.hw_timer[STEP_TIMER_INDEX].config.alarm_en = TIMER_ALARM_EN;
+    timer_set_alarm(STEP_TIMER_GROUP, STEP_TIMER_INDEX, TIMER_ALARM_EN);
 }
 
 void IRAM_ATTR Stepper_Timer_Stop()
diff --git a/RabbitGRBL/src/UserOutputs/AnalogOutput.cpp b/RabbitGRBL/src/UserOutputs/AnalogOutput.cpp
index 609b9b8..953b062 100644
--- a/RabbitGRBL/src/UserOutputs/AnalogOutput.cpp
+++ b/RabbitGRBL/src/UserOutputs/AnalogOutput.cpp
@@ -49,9 +49,8 @@ namespace UserOutput
             return;
         }
 
-        ledcSetup(_pwm_channel, _pwm_frequency, _resolution_bits);
-        ledcAttachPin(this->getPinNumber(), _pwm_channel);
-        ledcWrite(_pwm_channel, 0);
+        ledcAttach(this->getPinNumber(), _pwm_frequency, _resolution_bits);
+        ledcWrite(this->getPinNumber(), 0);
 
         MessageSender::SendMessage(EMessageLevel::Info, "User Analog Output:%d on Pin:%s Freq:%0.0fHz", this->getNumber(), pinName(this->getPinNumber()).c_str(), _pwm_frequency);
     }
@@ -76,7 +75,7 @@ namespace UserOutput
         }
 
         _current_value = numerator;
-        ledcWrite(_pwm_channel, numerator);
+        ledcWrite(this->getPinNumber(), numerator);
 
         return true;
     }