Permanent Slowdown after clicking menu

[elunesgraces]

Upon game loading with target 60FPS the FPS maintains itself. However, upon clicking anything in the menu bar and click off again, the FPS permanently drops to around 42 FPS.

I have repeated this several times with two different games (MMBN 3 and MMBN2) with exact same results. It does not appear to occur on the title screen, only during gameplay segments.

report slowdown.zip