It seems that I have the same problem with bluetooth connection. I had 7862 HU with Official Dudu OS 3.6 upgraded recently.
The HU still can connect automatically with my HUD without any problem, but had problem when connecting with my iphone 15. It lost connection with the iphone and it can only connect again after trying many times, but still lost again when the car restarted.
So every time I started the car, I have to try to connect HU with my phone via bluetooth. This problem didn't happen with the previous Dudu OS version.
Can anyone help me with this? Thank you.