Can you explain in more detail what exactly you mean?
I just discovered a bug that makes AP not draw any lines until you release your stroke (lift up your pen) – then the line is drawn. Is that what happens to you?
Or is is just slow in general?
One general advice is to not work 4K. But work in 2K and then scale up to 4K when finished. This sounds awful I know, but because of AP’s line engine there will be no difference – except for the responsiveness for you. 😉 You see, AP re-renders all your lines in full 4K, which means no degradation or blurring of any kind.
Anyway, if you were able to work fine in 4K on earlier versions, there’s probably something giving you the current problems. Let me know more, if possible. Thank you!