playback issue

Hey so i am new to all of this so im not gnna really know what im doing but for the past 3 days my playback is not running at smooth 60 fps. it lags and drops to 59.8 and sometimes 50 or 56 and if i pause the clip rewind it to where it was lagging then play it goes at 60 then drops again at a diffrent time point. this makes the audio choppy and ahead of the video which is really annoying. this didnt happen to me when i made my other two videos with resolve only recently this has been happening please help.

First thing to do is list your system details including OS, GPU, RAM, Resolve version, etc. Also the origin of the video. Is it HD or UHD? It's possible your GPU may not be powerful enough.