My 905 was doing the same thing last Monday, had two GM vehicles here that would not connect on a bet going back the Manufacture screen.  I called support and the wanted to do a TV connect and see what ws going on.  I had to update my shop wireless router to do TV and by the time I got that done, the Maxisys went back to connecting fine. It still does on occasion drop out, but reboot and it usually wil connect. Seems like this started after  1.20 update.

 yes bill Iam having the same problem with my 905, this started happening after the last 2 updates,at least thats when i noticed,can't even work on gm vehicles anymore, it crashes all the time,lucky for me that i have a tech2 and mdi or i will be mad as hell, as soon as i think we getting somewhere they screw something up,i have sent a complaint regarding this issue, I think ota 1.2 update its to be blame but there is no way to uninstall this one, another mistake, well hopefully it gets fix soon 

 My Maxisys Pro is doing the same thing in all makes not just GM, right now it's  almost useless, it also happened after the last update (v1.20) I'm just waiting for the next system update, I hope  it gets fixed.

 Just downloaded the latest Ota908 update for my Maxisys and seems like it is fixed!