As already mentioned I'm currently facing a very similar problem to this one:
https://b4x.com/android/forum/threads/solved-ide-disconnects.171150/
I decided to open a new thread, since this one is marked as solved.
It seems like my IDE connects to the debugger, but looses connection after the compiled app is installed (compilation and installation works fine).
The app icon appears on the home screen and the Bridge app switches to my application - but then is stuck at "Waiting for IDE to connect..."
The IDE shows "Trying to connect to device..." in the bottom blue bar.
Re-installation of the bridge as well as restarting both the PC and tablet did not help.
The whole process worked absolutly fine last week - and i haven't changed anything (besides some lines of code).