I'm not sure if this is a bug or some subtle logical consequence of something I don't understand. I'm using the latest (09 Apr) appimage but I've seen it for a long time:

If I make a brush preset with a pattern enabled, that brush always shows as dirty with the little additional icon at the top left of the brush preset icon in the brush presets docker. Note: This is not a tweak on an existing brush preset, it's a new brush preset made using Save New Brush Preset in the Brush Editor.

If I use the Brush Editor, it shows a yellow triangle to indicate that the settings have changed from default, so I press the reload icon and that goes away and the dirty icon goes away from the brush preset icon.

If I then use that brush preset to paint, the dirty icon comes back. (I also get an asterisk after the brush preset name and I think this is due to an Instant Preview caution notice which is also displayed inside the Brush Editor.)

If I turn off Temporarily Save Tweaks To Presets, the dirty icon and the asterisk go away but the Brush Editor still says that the settings have changed from default.

This is confusing. Is it a bug?

I have that behavior I just couldn't figure what presets where affected and why as I was putting together a bundle, thus didn't put much thought into it purposely. Similar issue was present back when the Brush Editor got some big changes I remember, after a while it was fixed but it is practically the same (a least from the users pov). To me it looks like a bug, if you report I can add/confirm behavior.

Bug reported here - thank you https://bugs.kde.org/show_bug.cgi?id=406427