I tested this under similar conditions. The list of contacts and call history work. I initiated the Bluetooth pairing from the vehicle infotainment system and said “yes” to all prompts on the phone.
Sending and receiving SMS is not supported, but this was always the case.
A things pops up sometimes: while deleting typed text the tap on delete removes two letters a once instead just one. If you delete severel letters in a row (with hold or additional taps on delete) this affects just the first of those taps and starts again when you type or set the cursor to another position.
I also noticed that bluetooth audio to my car system started to have bery short gaps/stops now like I already had (but mor often) on my Xperia 10 III (actual Volkswagen Media system). But this just seems to happen with Hi-Res Audio File and just with Bluetooth in my car - not with other Bluetooth speakers.
Good hint, don’t know, but will investigate. A test right now worked well in SFOS notes, but as a write here it was first okay too but reappears after some words. Now it’gone again, comes back while just type this and test it, but for now just under Android. So I switched to Notes again, no problemm there, switch to android browser, happens again, then not. But I get no pattern why this happens. But seems just to affect android.
There’s definitely some bugs left with typing in Android apps, for example when backspacing on a longer text, it all goes haywire and starts deleting random parts, but then also duplicating other parts (even though you’re still backspacing), and so on. So I would guess your problem is closely related to the other keyboard bugs in AppSupport.
I’ve noticed this gets worse: the longer the phone is running, the more CPU lipstick starts to consume. It slowly but steadily increases and never goes back down. My current uptime is a bit over 10 hours and lipstick is already consuming 9.2% of CPU. Every couple of minutes, another .1% gets added. Right now the only open apps are SFOS Forum Viewer and Crest. I’ve turned off AppSupport just to check, but lipstick is still at 9.2%.