Optical Flow not working

Hi, I've used Premiere Pro a lot over the past 2 to 3 years, so I'd say I have moderate experience using it. I use a L13 Yoga with an Intel i5 10th gen, 8gb of sodimm ram and integrated graphics. Despite the bad specs Premiere runs fine on my laptop.

It has never happened to me before but I now have a problem with optical flow, sometimes it works fine, but sometimes it just will not create the extra frames no matter what I do, I've had a look at other discussions and solutions, render and replace just breaks my clip entirely and it becomes a frozen frame, with the speed ramps messed up, changing the sequence frame doesn't work either, nesting and then reapplying optical flow doesn't help, removing the sfx doesn't help because it's a raw clip in the first place. What ever I do the certain part of the clip will just be choppy no matter what, even if the clip right next to it has optical flow working perfectly fine.
Please help.