[Q] USB connnection to computer stopped working after lolipop upgrade topic

Hey

Just updated the ONE DE (2 of them ) to the latest lolipop official.
both phones updated perfectly, but one of them has a problem:
when connected to the computer - it recognizes being connected to the computer for about one second, and then it disconnects (most of the times it pops up it pops up HTC sync).
after a second, it disconnects and usually it complains about USB host mode.

before the update, it connected to the computer with no problem.

any ideas?

thanks