Issue Summary
On my iQOO Z7 (Funtouch OS 15 on Android 14), selecting Kvæsitso as the default home app doesn’t stick—after a reboot or when the device is idle, the system unexpectedly reverts to the built-in launcher .

Steps to Reproduce
Go to Settings → Apps → Default Apps → Home App, and choose Kvæsitso.

Use the phone normally, then restart or lock/unlock the screen.

Press the Home button—now the system launcher appears instead 

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Expected vs. Actual
Expected: Kvæsitso remains the default launcher until manually changed.

Actual: The launcher setting randomly resets back to the stock system launcher 
Early Bird Club
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References:

Vivo Z9X (Funtouch OS) default-launcher reset reports 

EarlyBird forum: Default launcher resets after restart on Oppo-derived UIs 


XDA thread: Known Oppo issue with default-app reversion