Thanks for posting. There are many reasons why the gear will slip so a bigger picture of what all was going on would be needed to make an accurate determination of what the cause is. I’ll go in sometime this weekend and do a print on it and see how it functions.
Filament doesn’t tend to just break. It usually bends. Unless of course it has been left out. If that’s the case then the filament will begin to become brittle, because all filament is hygroscopic some more than others. It’s recommended if you aren’t using the filament to place it back into the bag it came in along with the desiccant pack to prevent moisture from absorbing.
If its already brittle then you can always dry it back out. There are a few different ways. Either with a toaster oven, a food dehydrator, or this diy method with an incandescent light a dowel and a 5 gallon bucket.