Problem with midi notes not ending and automatic portamento

[anoma]

So I'm having this problem where I have a bass track that has a pretty long portamento for specific segments when the notes are overlapping, but after the track plays for exactly 8 bars, every following note is affected by the portamento when the notes are clearly separate. No matter where I start it after 8 bars it kicks in, and even when I freeze it or bounce it down to audio it still has the same effect. I've considered that it's an issue within the third party plugin I'm using but I can't find any possible reason it could be happening. I'm also having a problem within the piano roll where I'll make something play for a quarter note then silence for the rest of the measure, but even after the note ends it continues playing out until another note commences. This happens randomly and seemingly has no pattern to it. Does anyone know what I can do to fix either of these? This is only the third project I've worked on since purchasing live 10 but I didn't have either problem within the other two projects, I even used the same bass patch in one of them. The plugin I'm using is Xfer Serum if that helps. Any advice would be appreciated!