Premiere Pro All the sudden skips frames at 60fps

I'm working on a Wedding Edit with a 4k UHD 24fps timeline. 

It's a 20-30 minute edit that's still in the works. I started out with converting alot of the 60fps footage to 24fps by slowing the footage down by 40%. It played back smooth without pausing any frames. 

I needed a break from the edit so I saved it and quit out of the application for a while. I come back and all the footage I slowed down is pausing frames when it didn't earlier. 

I didn't interpret the footage, I wanted to be able to have control over which clips I slowed down and didn't want convert the ones I didn't want in slow motion

I've been at this edit for a while and I don't want to go back through and have to re-edit all the video clips. Anybody have any solutions? I've posted spec pics. Premiere is Version 23.6.0