This has been happening since I first loaded up Krita several months ago (v. 28). I use the D. Revoy brush "deevad_1c_eraser-hard" because it gives a nice sharp edge when it erases. The thing is, sometimes, it actually paints in the selected color until I refresh the brush from the toolbar. It's not a big deal, I just press refresh and all is good and I don't know what setting in the brush engine would cause it to go off like that but I wanted to report it since it has been this way for awhile.

The example below shows the dark blue line through the paint that is actually the eraser "painting" with the color. The white line is after I clicked on refresh

Hi, please try to check if temporarily save tweaks to presets is selected. I hope that works for you!!

I do have it turned on but as I understand it that's a global setting, correct? Either all brushes or none