How to diagnose wi-fi on Android?

I'm an Android enthusiast, as most of you, and I installed Lineage OS on my Oneplus 6 two months ago. Everything works fine but not Wi-Fi that randomly disconnects from my router. In the end of the day the connection is unusable, disconnecting and recovering every 30 seconds. The Wi-Fi only stabilizes after a reboot. I have already discarded router and internet connection issues because other devices (including other non-lineage Android devices) works perfectly while I am suffering. I'm looking for a way to diagnose and solve this issue. What are your recommendations? I would appreciate every tip! Thanks! Environment information: - Oneplus 6 A6003 (enchilada) - Lineage 18.1 (Android 11 - 20210921-nightly-enchilada) - Router: Google Wi-Fi - Country: Brazil (not spanish, portuguese!) - other possible linked issues: bluetooth works fine with my headset, but has a similar issue on my car (only audio Android Auto on Ford media center)