Low Frame Rate

I'm not sure exactly when it started happening, but on my work PC, there is noticeable jaggedness to scrolling on my 75 Hz monitors. On my home PC, it's extremely laggy compared to my 144 Hz monitors. It didn't use to be like this. Firefox runs smooth as butter on both. It seems like LibreWolf is intentionally kneecapping its refresh rate. I tried changing the usual suspect flags, but no dice. What can I do to fix this? I much prefer LW to Firefox, and would like to return. But it's unusable to me in this state.