I did Mewtwo for the first few times yesterday, and ran into that twice. Second time fortunately wasn't that bad though, since it was at least frozen near the bottom. I saw it happen on Yveltal before, but I think Mewtwo is where it's a noticable issue.I can beat EX Mewtwo without power ups now o/
1 out of 4 times
I still get crappy odds though
Also I had a bug yesterday, in which I grabbed a Gengar token before it Mega evolved, and I was stuck with a normal Gengar token on the board the whole time. It wouldn't match with the Mega evolved ones and wasn't affected by their effect.
And maybe it's because I had a nice team for it, but Mewtwo doesn't seem that bad. Not good, but less "this feels unwinnable" than Blaziken did to me. Got a win in my first 7 tries or so, no items. And I got a 4% out of 4 seconds left, so at least it seems doable to escape the dreaded 1% odds. Going to take a number more tries before I get consistent, though.