Looping While Playback Causes Hang

[hexSPA]

Hi. In nearly-finished projects, attempting to loop a section during playback sometimes results in a non-responsive reaper. When the project is light, reaper will display a red indicator in the transport. However, the the project is larger, reaper has been seizing up and acting strangely.

9900K
32GB
21H1
6.38
RME Babyface Pro FS Driver 1.20, HW Revision 127
3rd Party VSTs; specifically with Meldaproduction and Sonimus but also reaper itself with looping during playback (as mentioned in my other post).

EDIT: May have been caused by a buggy VST (non-Melda). Will update if the issue returns.