I just wired up my LLT smart BMS and I am having the exact same issue - all seems well, but it won’t read any data from the BT module. I did not short anything to my knowledge.
Tried disconnecting the BT module, reinstalling the app, etc.
Also, I noticed it makes a high pitched noice when it’s connected. I assume that’s normal?
Edit: This is on iOS app, 12s, all cell voltages at 3.69V