I think I have found what's causing the bug. I've assigned "a" and "d" keys for quick brush size increase/decrease. And so when I use a custom brush, exit it to use the regular brush, and then increase/decrease size the custom brush opens back up
It happens even if I close the Brush Manager Pro window for some reason
Viewing post in Brush Manager Pro For Aseprite comments
Hiii I just released the v0.9.1 patch, and the bug should be fixed now! The plugin now properly stops all processes and hotkeys when you close the window (fingers crossed it actually behaves this time xd).
Glad you pointed out the exact cause! Hopefully, it works smoothly now. If u find any other issues, just let me know ₍ᐢ. .ᐢ₎