SUMMARY After switching to a Filter engine brush, then to another preset, Instant Preview stays off. STEPS TO REPRODUCE 1. Open the Brush settings 2. Enable Instant Preview 3. Select a Filter brush preset 4. Switch to a different brush preset / engine OBSERVED RESULT Instant Preview is now toggled off and has to be reenabled. EXPECTED RESULT Instant Preview only turns off temporarily as long as it cannot be used. SOFTWARE/OS VERSIONS Tested in 4.2.6 and master.
I can confirm this for the 4.3.0 pre-alpha (git 307e910). It also happens if you select brushes from the brush preset dockers (then check them in the brush editor).
A possibly relevant merge request was started @ https://invent.kde.org/graphics/krita/-/merge_requests/813
Git commit b96780cc8726f4c6eec082a0ce1d77cdf1034d65 by Dmitry Kazakov, on behalf of Black Cat. Committed on 19/04/2021 at 06:15. Pushed by dkazakov into branch 'master'. Fix Instant Preview state in Brush Editor Instant Preview checkbox was not restoring state after switching from brush engine that blocks it. M +4 -0 libs/ui/widgets/kis_lod_availability_widget.cpp https://invent.kde.org/graphics/krita/commit/b96780cc8726f4c6eec082a0ce1d77cdf1034d65