Y-Axis Belt keeps slipping, getting loose  

Y-Axis Belt keeps slipping, getting loose

Good day fellow Prusa enthusiasts!

I have a Prusa Mini that I have been happily printing on since March. Recently I've been having issues with the Y-axis belt. It just simply won't stay tight. I've gone and retightened it at the Y-axis belt holder under the build plate a few times now, but the belt slips on the teeth and gets loose again during a print.

Is it possible that I am putting it TOO tight in the holder? It will be loose and only have a grip on about 6 teeth of the belt which when printing circles like the benchy chimney/smokestack will make them ovals which is how I noticed the issue to begin with. I'll retighten it to be holding 8-9 teeth. I go to print a benchy to make sure my circles are not ovals and by the time it gets to the smokestack/chimney the belt has slipped and it is printing ovals again.

It seems that the issue shows up when printing at 100% speed, as when I print slower like 75%, it does not slip and the benchy turns out great as expected.

I am in the middle of printing a new Y-axis belt holder to see if that will fix things. I think my current part is F1 vs R1? I'd pull the part to verify but in the middle of a print haha.