JUCE7 Audio Plugin causes Studio One slow GUI response

On Windows 7,
After moving to JUCE7, opening an Audio Plugin under Studio One makes the entire GUI of the DAW run very slow. Closing the Plugin Editor and everything is back to normal.
Created a whole new plugin (Basic) from scratch and issue still happens, while it does not happen with JUCE 6.x.x
(did not test on a different OS or DAW yet)

Noticed that there were changes in graphics regarding
JUCE_COREGRAPHICS_RENDER_WITH_MULTIPLE_PAINT_CALLS and JUCE_COREGRAPHICS_DRAW_ASYNC,
But could not find how it is related to the plugin or how to work around it,
Any clue?