LG VX810 Random App crashes

[Xybix]

Ever since my LG VX810 upgraded to Lollipop I've experienced 2 odd things:

1. It runs very slow.  When playing simple games the system hangs and doesn't react.  Refresh times on the screen with action games like Clash of Clans or Boom Beach is S L O W

2. When I'm at random locations - airport is one - apps I'm using will randomly crash for no reason. Doesn't matter if wifi is on or off.  Gets to the point where the tablet is useless in those locations - can't read mail, play games ...etc.

Any thoughts?  The only thing I have yet to do is factory reset the tablet and rebuild it, but I loathe doing that.

Thanks in advance.