diff --git a/Marlin/Configuration_adv.h b/Marlin/Configuration_adv.h
index 8e66d7555d..82cfc99b30 100644
--- a/Marlin/Configuration_adv.h
+++ b/Marlin/Configuration_adv.h
@@ -4222,13 +4222,17 @@
 #endif
 
 /**
- * WiFi Support (Espressif ESP32 WiFi)
+ * Native ESP32 board with WiFi or add-on ESP32 WiFi-101 module
  */
-//#define WIFISUPPORT         // Marlin embedded WiFi management
+//#define WIFISUPPORT         // Marlin embedded WiFi management. Not needed for simple WiFi serial port.
 //#define ESP3D_WIFISUPPORT   // ESP3D Library WiFi management (https://github.com/luc-github/ESP3DLib)
 
-#if ANY(WIFISUPPORT, ESP3D_WIFISUPPORT)
-  //#define WEBSUPPORT          // Start a webserver (which may include auto-discovery)
+/**
+ * Extras for an ESP32-based motherboard with WIFISUPPORT
+ * These options don't apply to add-on WiFi modules based on ESP32 WiFi101.
+ */
+#if ENABLED(WIFISUPPORT)
+  //#define WEBSUPPORT          // Start a webserver (which may include auto-discovery) using SPIFFS
   //#define OTASUPPORT          // Support over-the-air firmware updates
   //#define WIFI_CUSTOM_COMMAND // Accept feature config commands (e.g., WiFi ESP3D) from the host
 
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index 4b56204db5..cfc3b20cd5 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -3810,12 +3810,20 @@ static_assert(_PLUS_TEST(3), "DEFAULT_MAX_ACCELERATION values must be positive."
 /**
  * Sanity check WiFi options
  */
-#if ENABLED(ESP3D_WIFISUPPORT) && DISABLED(ARDUINO_ARCH_ESP32)
-  #error "ESP3D_WIFISUPPORT requires an ESP32 MOTHERBOARD."
-#elif ENABLED(WEBSUPPORT) && NONE(ARDUINO_ARCH_ESP32, WIFISUPPORT)
-  #error "WEBSUPPORT requires WIFISUPPORT and an ESP32 MOTHERBOARD."
-#elif ALL(ESP3D_WIFISUPPORT, WIFISUPPORT)
-  #error "Enable only one of ESP3D_WIFISUPPORT or WIFISUPPORT."
+#if ALL(WIFISUPPORT, ESP3D_WIFISUPPORT)
+  #error "Enable only one of WIFISUPPORT or ESP3D_WIFISUPPORT."
+#elif ENABLED(ESP3D_WIFISUPPORT) && DISABLED(ARDUINO_ARCH_ESP32)
+  #error "ESP3D_WIFISUPPORT requires an ESP32 motherboard."
+#elif ALL(ARDUINO_ARCH_ESP32, WIFISUPPORT)
+  #if !(defined(WIFI_SSID) && defined(WIFI_PWD))
+    #error "ESP32 motherboard with WIFISUPPORT requires WIFI_SSID and WIFI_PWD."
+  #endif
+#elif ENABLED(WIFI_CUSTOM_COMMAND)
+  #error "WIFI_CUSTOM_COMMAND requires an ESP32 motherboard and WIFISUPPORT."
+#elif ENABLED(OTASUPPORT)
+  #error "OTASUPPORT requires an ESP32 motherboard and WIFISUPPORT."
+#elif defined(WIFI_SSID) || defined(WIFI_PWD)
+  #error "WIFI_SSID and WIFI_PWD only apply to ESP32 motherboard with WIFISUPPORT."
 #endif
 
 /**
diff --git a/Marlin/src/module/temperature.cpp b/Marlin/src/module/temperature.cpp
index c7e35c5754..6139ebe120 100644
--- a/Marlin/src/module/temperature.cpp
+++ b/Marlin/src/module/temperature.cpp
@@ -3080,7 +3080,9 @@ void Temperature::init() {
 #if HAS_THERMAL_PROTECTION
 
   #pragma GCC diagnostic push
-  #pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+  #if __has_cpp_attribute(fallthrough)
+    #pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+  #endif
 
   Temperature::tr_state_machine_t Temperature::tr_state_machine[NR_HEATER_RUNAWAY]; // = { { TRInactive, 0 } };
 
@@ -3978,7 +3980,9 @@ void Temperature::isr() {
   switch (adc_sensor_state) {
 
     #pragma GCC diagnostic push
-    #pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+    #if __has_cpp_attribute(fallthrough)
+      #pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+    #endif
 
     case SensorsReady: {
       // All sensors have been read. Stay in this state for a few
diff --git a/buildroot/tests/esp32 b/buildroot/tests/esp32
index a0f79107cf..2229b950c6 100755
--- a/buildroot/tests/esp32
+++ b/buildroot/tests/esp32
@@ -12,8 +12,8 @@ set -e
 restore_configs
 opt_set MOTHERBOARD BOARD_ESPRESSIF_ESP32 TX_BUFFER_SIZE 64 \
         WIFI_SSID '"ssid"' WIFI_PWD '"password"'
-opt_enable WIFISUPPORT WEBSUPPORT GCODE_MACROS BAUD_RATE_GCODE M115_GEOMETRY_REPORT REPETIER_GCODE_M360
-exec_test $1 $2 "ESP32 with WIFISUPPORT and WEBSUPPORT" "$3"
+opt_enable WIFISUPPORT WEBSUPPORT OTASUPPORT GCODE_MACROS BAUD_RATE_GCODE M115_GEOMETRY_REPORT REPETIER_GCODE_M360
+exec_test $1 $2 "ESP32 with WIFISUPPORT and WEBSUPPORT and OTASUPPORT" "$3"
 
 #
 # Build with TMC drivers using hardware serial
diff --git a/buildroot/tests/mks_tinybee b/buildroot/tests/mks_tinybee
index 0351946d0a..d3b258051b 100755
--- a/buildroot/tests/mks_tinybee
+++ b/buildroot/tests/mks_tinybee
@@ -10,11 +10,9 @@ set -e
 # Build with ESP3D WiFi, OTA and custom WIFI commands support
 #
 restore_configs
-opt_set MOTHERBOARD BOARD_MKS_TINYBEE TX_BUFFER_SIZE 64 \
-        WIFI_SSID '"ssid"' WIFI_PWD '"password"' \
-        SERIAL_PORT_2 -1 BAUDRATE_2 250000
-opt_enable ESP3D_WIFISUPPORT WEBSUPPORT OTASUPPORT WIFI_CUSTOM_COMMAND
-exec_test $1 "$2" "MKS TinyBee with ESP3D_WIFISUPPORT" "$3"
+opt_set MOTHERBOARD BOARD_MKS_TINYBEE TX_BUFFER_SIZE 64 SERIAL_PORT_2 -1 BAUDRATE_2 250000
+opt_enable ESP3D_WIFISUPPORT
+exec_test $1 $2 "MKS TinyBee with ESP3D_WIFISUPPORT" "$3"
 
 #
 # Build with LCD, SD support and Speaker support