Try SD-BC6. It's the same module, but another driver.Thanks for you answer. It's a bad story since I tried a lot of android 10.
So I tried WQ BC6, it's the same BUT good news ! I think the problem is ViperFX because I removed from Magisk and it is working (like this morning when I installed clean V5 without V4a)
I removed "Bluetooth internet sharing" too in "factory settings / other" so I'm not sure at 100%...
If it help anyone with this problem, I will test more but I make 8/10 calls w/o problem since 15 minutes.
(Edit) sh.... I closed the car and tried again 10 minutes later ... crash and reboot again (after 3 seconds of call) grrrr