Splotches while hovering while painting over inverted high pass filter layer

[Richard Liu]

I have inverted a High Pass live filter layer and am trying to paint back in just the parts that I want.  When I hover with the paint brush over the image Affinity Photo creates a trail of black splotches.

Affinity Photo 1.7.1 on macOS 10.13.6

Here is a screen movie:  https://drive.google.com/open?id=1viEQnHnmqgz52_vJxko7EZAiJZF_-d4m

[Richard Liu]

This bug is still present in the latest beta, RC3.  I will post this there as well.

[MEB]

Hi Richard Liu,
If you go to Affinity Preferences, Performance section and untick Metal compute acceleration does it still behaves the same way? Do you mind attaching a screenshot of your Mac specs please (menu Apple > About This Mac). Thank you.

[Richard Liu]

In fact, with Metal still active, I deleted the High Pass layer, recreated it, inverted it, and tried again, and was able to do what I couldn't before.  I'm puzzled about the cause of the problem, and am not so naive as to assume it won't happen again.   As I saved the working version of the .afphoto file over the misbehaving one, I would have to whether I can find it in Time Machine in order to try the same operation without Metal.  Should I?  It doesn't seem that many people have encountered this or related problems, does it?  And someday ... real soon now ... I'll upgrade to 10.14, which, if I recall correctly, corrects some problems with Metal in 10.13.

Here are the specs that you requested: