Here is some more information about my system.
My Display resolutions are:
1) ML control monitor: 1680 x 1050 (Desktop resolution), 1920 x 1080 (Active signal resolution)
2) Monkey's monitor: 1280 x 1024 (Desktop resolution), 1920 x 1080 (Active signal resolution)
3) The monitor mirroring monkey's monitor: 1280 x 1024 (Both desktop and active signal resolutions)
Display memory (VRAM): 128MB
Graphic card: Intel(R) UHD Graphics 630
I tried changing the refresh rate for all three monitors to 60Hz and also changing the frame rate of my movies to 60fps. That unfortunately did not fix the problem either.
I did look at the actual vs. supposed presentation times, and it seems that my frames are on average 13.5 ms late, which is close to the duration of each frame which is 13.3ms.The website crashed every time I tried attaching one of my bhv2 files, so I couldn't provide the full data on the issue.