Modpack version
1.59a

Can the issue be reproduced?
Yes

Logs
No Crash Log

Issue
After a period of time all movements (using WASD) are amplified significantly resulting in my character being thrown about/ off cliffs at slight touches.
FPS significantly tanks at this point
Random textures appear either in the sky or at set y-levels clipping through boxes

EDIT: Seems like changing the BetterFPS algorithm and restarting fixed the issue