Try a factory reset - only takes bout an hour.
I guess I was lucky enough to be planning a cleanup anyway - but the reset after having all types of issues did the trick. No more issues at all.
- wifi on/off
- random call placing
- network unavailable (even though wifi was connected)
I would also suggest not using the facial recog lock as it seems to eat up resources.
i've suggested this in other threads. i know people think it's a big deal, but it really isn't. back up anything you will need and wipe the phone. 9 times out of 10 it will be good as new. yeah...you have to spend some time setting back up your accounts and home screens, but it's really not that bad. also, there is a new app in the market called Carbon that will backup up data to your pc (none of the other backup apps will back up data). i think that would be more of a hassle than just setting up everything yourself, but for those who feel the need to backup and then restore everything (although it kind of defeats the purpose of wiping the phone with a factory reset), there is that option.
glad you got your thunderbolt working well!!!!!