diff --git a/tasmota/support_tasmota.ino b/tasmota/support_tasmota.ino
index 0fbcbb615..054d830cc 100644
--- a/tasmota/support_tasmota.ino
+++ b/tasmota/support_tasmota.ino
@@ -969,6 +969,9 @@ void Every250mSeconds(void)
         SettingsSave(1);  // Free flash for OTA update
       }
       if (ota_state_flag <= 0) {
+#ifdef USE_COUNTER
+        CounterInterruptDisable(true);  // Prevent OTA failures on 100Hz counter interrupts
+#endif  // USE_COUNTER
 #ifdef USE_WEBSERVER
         if (Settings.webserver) StopWebserver();
 #endif  // USE_WEBSERVER
@@ -1000,15 +1003,6 @@ void Every250mSeconds(void)
 
             char *bch = strrchr(mqtt_data, '/');                       // Only consider filename after last backslash prevent change of urls having "-" in it
             if (bch == nullptr) { bch = mqtt_data; }                   // No path found so use filename only
-/*
-            char *ech = strrchr(bch, '.');                             // Find file type in filename (none, .bin or .gz)
-            if ((ech != nullptr) && (0 == strncasecmp_P(ech, PSTR(".GZ"), 3))) {
-              char *fch = ech;
-              *fch = '\0';
-              ech = strrchr(bch, '.');                                 // Find file type .bin.gz
-              *fch = '.';
-            }
-*/
             char *ech = strchr(bch, '.');                              // Find file type in filename (none, .ino.bin, .ino.bin.gz, .bin, .bin.gz or .gz)
             if (ech == nullptr) { ech = mqtt_data + strlen(mqtt_data); }  // Point to '/0' at end of mqtt_data becoming an empty string
 
@@ -1055,6 +1049,9 @@ void Every250mSeconds(void)
         ResponseAppend_P(PSTR("\"}"));
 //        restart_flag = 2;          // Restart anyway to keep memory clean webserver
         MqttPublishPrefixTopic_P(STAT, PSTR(D_CMND_UPGRADE));
+#ifdef USE_COUNTER
+        CounterInterruptDisable(false);
+#endif  // USE_COUNTER
       }
     }
     break;
diff --git a/tasmota/xdrv_01_webserver.ino b/tasmota/xdrv_01_webserver.ino
index 112b9ac7f..b94a2a902 100644
--- a/tasmota/xdrv_01_webserver.ino
+++ b/tasmota/xdrv_01_webserver.ino
@@ -2600,7 +2600,7 @@ void HandleUploadDone(void)
   MqttRetryCounter(0);
 #ifdef USE_COUNTER
   CounterInterruptDisable(false);
-#endif
+#endif  // USE_COUNTER
 
   WSContentStart_P(S_INFORMATION);
   if (!Web.upload_error) {
@@ -2677,8 +2677,8 @@ void HandleUploadLoop(void)
     } else {
       MqttRetryCounter(60);
 #ifdef USE_COUNTER
-      CounterInterruptDisable(true);
-#endif
+      CounterInterruptDisable(true);  // Prevent OTA failures on 100Hz counter interrupts
+#endif  // USE_COUNTER
 #ifdef USE_EMULATION
       UdpDisconnect();
 #endif  // USE_EMULATION
@@ -2876,7 +2876,7 @@ void HandleUploadLoop(void)
     MqttRetryCounter(0);
 #ifdef USE_COUNTER
     CounterInterruptDisable(false);
-#endif
+#endif  // USE_COUNTER
     Web.upload_error = 7;  // Upload aborted
     if (UPL_TASMOTA == Web.upload_file_type) { Update.end(); }
   }
diff --git a/tasmota/xsns_01_counter.ino b/tasmota/xsns_01_counter.ino
index 73c19322e..5b6de4e4c 100644
--- a/tasmota/xsns_01_counter.ino
+++ b/tasmota/xsns_01_counter.ino
@@ -49,7 +49,6 @@ struct COUNTER {
 uint32_t last_cycle;
 uint32_t cycle_time;
 
-//void ICACHE_RAM_ATTR CounterUpdate(uint8_t index) {
 void ICACHE_RAM_ATTR CounterIsrArg(void *arg) {
   uint32_t index = *static_cast<uint8_t*>(arg);
 
@@ -94,15 +93,15 @@ void ICACHE_RAM_ATTR CounterIsrArg(void *arg) {
           // add 100.000 cpu ticks to ensure right step calculation
           uint32_t steps = (current_cycle-last_cycle+100000)/(clockCyclesPerMicrosecond() * 10000);
           cycle_time = (current_cycle-last_cycle)/steps;
-          #ifdef ESP8266
+#ifdef ESP8266
             pinMode(Pin(GPIO_PWM1, index), OUTPUT);
             uint32_t high = (cycle_time * 5) / 1023;
             uint32_t low = cycle_time - high;
             // Find the first GPIO being generated by checking GCC's find-first-set (returns 1 + the bit of the first 1 in an int32_t
             startWaveformClockCycles(Pin(GPIO_PWM1, index), high, low, 0, -1, 0, true);
-          #else
+#else  // ESP32
             analogWrite(Pin(GPIO_PWM1, index), 5);
-          #endif
+#endif  // ESP8266 - ESP32
         }
         last_cycle = current_cycle;
       }
@@ -120,27 +119,7 @@ void ICACHE_RAM_ATTR CounterIsrArg(void *arg) {
     }
   }
 }
-/*
-void ICACHE_RAM_ATTR CounterUpdate1(void)
-{
-  CounterUpdate(0);
-}
 
-void ICACHE_RAM_ATTR CounterUpdate2(void)
-{
-  CounterUpdate(1);
-}
-
-void ICACHE_RAM_ATTR CounterUpdate3(void)
-{
-  CounterUpdate(2);
-}
-
-void ICACHE_RAM_ATTR CounterUpdate4(void)
-{
-  CounterUpdate(3);
-}
-*/
 /********************************************************************************************/
 
 void CounterInterruptDisable(bool state) {
@@ -172,20 +151,15 @@ bool CounterPinState(void)
 
 void CounterInit(void)
 {
-//  typedef void (*function) () ;
-//  function counter_callbacks[] = { CounterUpdate1, CounterUpdate2, CounterUpdate3, CounterUpdate4 };
-
   for (uint32_t i = 0; i < MAX_COUNTERS; i++) {
     if (PinUsed(GPIO_CNTR1, i)) {
       Counter.any_counter = true;
       pinMode(Pin(GPIO_CNTR1, i), bitRead(Counter.no_pullup, i) ? INPUT : INPUT_PULLUP);
       if ((0 == Settings.pulse_counter_debounce_low) && (0 == Settings.pulse_counter_debounce_high) && !Settings.flag4.zerocross_dimmer) {
         Counter.pin_state = 0;
-//        attachInterrupt(Pin(GPIO_CNTR1, i), counter_callbacks[i], FALLING);
         attachInterruptArg(Pin(GPIO_CNTR1, i), CounterIsrArg, &ctr_index[i], FALLING);
       } else {
         Counter.pin_state = 0x8f;
-//        attachInterrupt(Pin(GPIO_CNTR1, i), counter_callbacks[i], CHANGE);
         attachInterruptArg(Pin(GPIO_CNTR1, i), CounterIsrArg, &ctr_index[i], CHANGE);
       }
     }