Awsome for your superfast response!!!!!!!!! 
Version is latest. 21. Really hope you can help! The code is written by an intern and when he stopped I dove into it. I made a lot of changes and already fixed some other issues, but now I am stuck. Especially beacuse it works fine for a random amount of time (somewhere between 5 minutes and an hour). I already did like 30 succesfull scans after a reset and than after 15 minutes it still worked like a charm. After an hour of no activity it suddenly got stuck at connecting...... It feels totally random...
Thanks again for your trouble!