We’ve been experiencing this issue as well since we updated to 8.0.11 (we were on 8.0.3 with D2D disabled before that).
Having multiple opened UI instances of our plugin on Windows (tested in Ableton and Bitwig*) makes actions like clicks unresponsive (from few to many seconds delays, to completely unresponsive and having to force quit the DAW). The animations keep running smoothly however.
When all instances use the software renderer, (`getPeer()->setCurrentRenderingEngine(0);`), there’s no issue. But if one or more instance use OpenGL (we allow to choose that per instance at runtime with an option), we experience the issue again. If everything uses OpenGL, then everything freezes instantly.
All of those cases were working fine on 8.0.3 (with D2D disabled) or on previous versions.
I’ve profiled (cpu + gpu), used Thread Visualizer, used JUCE_DIRECT2D_METRICS=1 with D2D metrics app, and I couldn’t find the issue.
Could the JUCE team investigate this issue? This prevents us from updating and benefiting from other improvements and bug fixes (and from using D2D).
* In Bitwig, there was no issue if the plugins were running in separate processes.
Edit: This post seems related as well UI freeze when using D2D or OpenGL on Windows, due to not using WM_PAINT