You are right! My so-called workaround only lasts for about a week after a reboot due to automatic optimization. I can almost confirm that the problem is caused by regular system optimization. The root cause is not the Bluetooth apps themselves, but rather one of their dependencies. I traced the dependency through Developer Options → Running Services → Bluetooth. A list of dependencies appears under Bluetooth, with the most suspicious items being SapService and Samsung Multi Connectivity. Somethings like that:
The SapService is related to the SIM card — SAP stands for SIM Access Profile — and it is not an app that can be found in the Apps menu. Anything named 'SIMxxx' is likely the target.
I have tried switching them to Unrestricted in the battery settings. So far, it has remained stable for over twelve hours. It’s very easy to test — just make a phone call to your voicemail; it’s usually free of charge.
Maybe you can try it and let me know your observations so we can work on it together.
