Problem:
On my machine the filament (PLA) wire breaks every time apart after a couple of hours after printing.
Solution:
Unknown, maybe you have one?
after print go to z-position 100mm or higher
The filament is known to break, usually after about 2 days, because of constant tension in a fixed position (= while not printing).
I found that putting the spool next to the fan near the extruder (Z-axis low) solve the problem. It stayed more than a week without having the filament snapping (then I used the printer again).
Anyway, if it happens, always extrude 2-3cm of filament before taking the remaining our of the extruder to avoid jamming it.
I have found if you leave the filament sitting out it can get to dry and becomes very brittle.
I have tried putting it in a freezer bag with a moist paper towel will help.
You have to figure out the timing.
If you leave it in there to long it absorbs to much moisture.
When not in use store it in a freezer bag.
Just my thoughts