I apologise, I've only just seen your post. Does it still do it with newer versions?
It could well be computer speed. There's been some speed improvements between versions, so it should now run better. So thats the most likely culprit. I'm planning on a full optimisation sweep of the game to get it as fast as possible for all players and hopefully that'll resolve your issues. It won't go through the normal Patreon exclusive week first because it's solely optimisation and any bugs that pop up.