So I just updated LOS 20 on my FP4, as usual, installing build 2-20230806-NIGHTLY-FP4, except this time my phone started behaving weirdly.
It all started yesterday evening after post installation reboot:
→ Everything was working, except Bromite browser not being able to access internet displaying the “turn off airplane mode” message. Obviously I wasn’t in airplane mode, I could browse the play store, reddit app, mails etc, without any problem.
I rebooted the device and the issue was gone.
Then this morning, at 8h30 precisely (no alarm clock set at this time), my phone started to continuously vibrate and at the same time to emit some kind of continuous tone (like the beep you got on older computers when displaying the BIOS except continuous).
It wouldn’t stop until a reboot.
Then this afternoon, everything was working, including Bromite, EXCEPT for Google Play Store that kept telling me it had no internet connection.
Again a reboot fixed that. I wonder what’s coming next 
I am rooted and been running LOS since the 19 version, updating every month without any issue so far.
Did anyone meet the same erratic behaviours recently ?
Edit:
Just as I finished writing this post, I had the issue where the browser did not work. It appears every webview can’t access the internet in all applications. Yet, I can receive and send whatsapp messages, browse app such as reddit, discord etc…
Again a reboot fixed it.