diff --git a/.gitignore b/.gitignore
index ea7ad925a8..e795ba3fb8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -117,3 +117,4 @@ via*.json
 /.claude_session
 /.remember/tmp/save-session.pid
 /.direnv/CACHEDIR.TAG
+/.gemini_session
diff --git a/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/config.h b/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/config.h
index 924e45b5ff..e9fd63dd8e 100644
--- a/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/config.h
+++ b/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/config.h
@@ -3,6 +3,16 @@
 
 #pragma once
 
+// Tight, strict combo window for a simultaneous 3-key press.
+// This ensures the fallback combo only fires when intended.
+#define COMBO_TERM 10
+#define COMBO_STRICT_TIMER
+
+// Use a more conservative debounce period (20ms is standard for Keychron)
+// but since we switched to 'sym_defer_pk' in rules.mk, this will now
+// require 20ms of STABILITY before a keypress is reported.
+#define DEBOUNCE 20
+
 // Always resolve combo keycodes from BASE (layer 0) so the
 // COMM+DOT+SLSH fallback combo fires regardless of the active layer.
 #define COMBO_ONLY_FROM_LAYER 0
diff --git a/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/keymap.c b/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/keymap.c
index 94c30c0c39..173888b756 100644
--- a/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/keymap.c
+++ b/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/keymap.c
@@ -169,6 +169,16 @@ bool process_record_user(uint16_t keycode, keyrecord_t *record) {
             if (record->event.pressed) {
                 caps_mod_held  = true;
                 caps_mod_timer = timer_read();
+                // If a real modifier is held, send a dummy key so the OS sees
+                // modifier+key rather than a bare modifier hold/tap. Without
+                // this, the OS never receives any keycode while the modifier is
+                // down and treats the eventual modifier release as a tap (e.g.
+                // GUI opening the app menu). KC_F24 is harmless and universally
+                // ignored by applications.
+                if (get_mods() & (MOD_MASK_GUI | MOD_MASK_ALT | MOD_MASK_SHIFT)) {
+                    register_code(KC_F24);
+                    unregister_code(KC_F24);
+                }
             } else {
                 if (caps_mod_ctrl_registered) {
                     unregister_code(KC_LCTL);
diff --git a/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/rules.mk b/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/rules.mk
index 256b50f150..a2e60506ae 100644
--- a/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/rules.mk
+++ b/keyboards/keychron/q5_max/ansi_encoder/keymaps/via/rules.mk
@@ -5,3 +5,5 @@ COMBO_ENABLE = yes
 CAPS_WORD_ENABLE = yes
 AUTOCORRECT_ENABLE = yes
 SRC += chord_unicode.c
+
+DEBOUNCE_TYPE = sym_defer_pk