My projects are visually lagging and being really buggy does anyone know why this is, my projects are fairly large

my specs are AMD Threadripper 1950x (16-core 32-threads 4.1GHz) CORSAIR Vengeance RGB 16GB (2x8GB) DDR4 3600MHz C18 EVGA GeForce GTX 1080 Ti

Why do my projects when they get bigger have no issues playing, 0 dropouts but when i try to move plugins around it visually lags for me and sometimes crashes... when i restart my browser it runs smoothly but goes down hill after a bit of time having it open? Can someone explain.