Vital: 3rd Party Plugin Glitch?

I wanted to experiment with Vital Synth ( https://vital.audio/ ) from the VST3 folder. I replaced the piano sound with it and inputted a few notes. After two bars in, a few of the inputted notes were sustaining even though I did not press play. The sustained notes stop playing until I click on a measure. But the sustained notes continue to play on top of the written notes when I press play. At a certain point, it sounds like a black midi until you cannot hear the original piece anymore.
I closed, opened up, and repeated the same process in case it was a one-time thing, but it occurred each time.