No physical button input when launching from other frontends on android

[unbelievableflavour]

I hope this is the right repo. Sorry if it aint.. I'm having an issue with Mupen64Plus-Next-GLES3. Whenever I launch this particular core from frontend different from retroarch. I sometimes don't have have input.

Expected behavior
core launched from command runs the game with buttons working

Actual behavior
core launched from command core runs the game without buttons working. Not even retroarch overlay's and such can be opened.

Steps to reproduce:
Launch an instance of mupen using the following config:

-n com.retroarch.aarch64/com.retroarch.browser.retroactivity.RetroActivityFuture
-e ROM /PATH/TO/FILE
-e LIBRETRO /data/data/com.retroarch.aarch64/cores/mupen64plus_next_gles3_libretro_android.so
-e CONFIGFILE /storage/emulated/0/Android/data/com.retroarch.aarch64/files/retroarch.cfg\n  
-e IME com.android.inputmethod.latin/.LatinIME
-e DATADIR /data/data/com.retroarch.aarch64
-e APK /data/app/com.retroarch.aarch64-1/base.apk
-e SDCARD /storage/emulated/0
-e EXTERNAL /storage/emulated/0/Android/data/com.retroarch.aarch64/files
--activity-clear-task
--activity-clear-top

Issue has been confirmed on the following devices:

• OS: Android 11, device: Retroid Pocket 3+
• Retroid Pocket 2+

Important
This issue does not happen with every game.

Try one of the following

• Harvest Moon 64(USA)
• Star Wars: Rogue Squadrons(USA)
• Super Smash Bros(USA)
• Tonic Trouble(USA)
• Rakugakids(EU)

Mentions
This issue has been mentioned multiple times before in other locations:

• physical gamepads not working parallel-n64#336
• Launching Mupen64plus GLES3 or Parallel64 Retroarch cores through Daijisho causes inputs to not register TapiocaFox/Daijishou#181
• Input not being recognized for N64 using front end. RetroArch#15109

Frontends where this happens

• Retroid Launcher
• Daijisho
• Dig
• Launchbox

CANNOT reproduce this on the following device
OS: Google Pixel 3A with Xbox controller. works perfectly there..

[unbelievableflavour]

Workaround
The issue doesn't occur when you hold down a button when retroarch starts opening until the game has started. (for instance, the A button).

[unbelievableflavour]

Better Workaround

Change this setting like so:

1. Go to Retroarch > Settings > Input > Polling Behaviour
2. Change to "Early"
3. Save configuration.
4. Restart retroarch.

[m4xw]

Not a bug, other frontends might not be implementing this function https://github.com/libretro/mupen64plus-libretro-nx/blob/develop/libretro/libretro.c#L921-L924