2 Canon 5D4 issues - has anyone had these?

Couple of issues started to escalate with my 5D4 and was wondering whether anyone else has had them, before I sent the thing for repair... 

1 - USB
For 2.5 years I've been connecting the cam via supplied USB cable to my PC to download photos successfully, no issues. 

Now when I connect it, For around 5 seconds it appears to connect correctly (EOSutilty pops up and a computer symbol appears on the camera screen). Then the screen goes blank on the camera, EOS utilty3 says "no connection" and the camera becomes totally unresponsive. There's a slight glow to the back screen - when you remove the USB cable this slight glow disappears. The camera is totally locked - the LCD settings are still visible, no buttons work, no wheels work. You have to remove the battery and replace to get the camera working again. 

2 - Err 01
I know this is camera/lens contact - I've cleaned this we advised with a dry cloth on both the camera and all 6 lenses I've tested it with. All lenses work just fine on a 5D3 I have. 

It worsened yesterday, I've occasionally seen a 01 and just "wiggled" the lens a little bit to move the contacts a little and we're back in action. 

So yesterday on a workshop it was causing issues with 4 different lenses - so its not the lenses. 
With the lens correctly attached, if I lightly "twist" the lens to the left, the camera "usually works" - however, if I apply light pressure to the right - e.g. twisting a polariser, zooming etc.  - I get the Err 01 

This becomes intolerable using tilt-shift lenses as it almost never worked yesterday. 
Live view would breifly work, then switch off. 

Quite often, the camera freezes up needing you to switch it off and back on (though no need to pull the battery out).

Both things are very recent - not sure if they're related, but it's a hell of a coincidence. 

Has anyone had any success with things like factory reset - or is this just a case of sending it to a repair centre? 
Thanks in advance 
Ade