Paint brush tool works initially but starts to hit an "invisible border"

[xenrin]

I'm not really sure how to describe this problem, and I haven't found a way to reproduce this problem consistently, but it's been plaguing me for the last 2 years (since I bought the program). I've tried searching for it, but it seems that no one else has been having this issue, or I don't know how to search for it.

Today I finally decided to screen-capture it. Watch the upper left corner. The first half is me moving the paint brush tool over the invisible border, the second half is me painting over it. The brush was behaving fine beforehand, and restarting the program causes the invisible borders to disappear. They always look like alternating semicircles; there can be more than one string of them at a time; and they sometimes join together. You can paint normally until you reach the border and then the brush stops; you can paint on either side of the border unlike a mask.

This is a plain pixel layer with no masks or filters set, using the default round brush at a low flow and low hardness (but the issue happens even at full opacity/flow) in Affinity Photo 1.8.5 but the issue goes back to at least 1.7. I've never had the problem happen immediately after opening a file, it always happens after I've been working for a while.

 

[Mark Ingram]

Can you attach your document?

[xenrin]

Unfortunately (or I guess, fortunately for me when I'm trying to work) this issue doesn't seem to be tied to any specific document, because closing the program and opening the document again fixes it. I left Photo open all day today and periodically tried to trigger the invisible borders, but none showed up.

When the issue does show up it will export exactly as displayed. The only fix I've found is shutting down Photo and re-opening.

[xenrin]

After some more experimenting, I think you can close this as user error. I was able to replicate a similar effect by laying down a very low opacity line and then switching from Paint Brush to Color Replacement Brush and painting over it. Since they're on the same key I can see how it could easily happen, though I usually make a point of checking which "B" tool I ended up on. The annoying transparent borders probably just annoyed me to the point of forgetting to double-check.