I have occasionally seen this with previous versions. With the latest update its occurring at a significantly higher frequency (approx. 50% of attacks). I've even had a few battles where no values appeared for the entire battle.
Yeah, I've been continuing my game thus far and it's definitely common.
The really good news: not a single DX error or OOM yet. On top of that the game performance seems to be extremely crisp. I'm noticing a huge improvement on my end.