Old Prusa PETG filament?  

Old Prusa PETG filament?

I've been printing the parts for the  'Prusa MMU3 Upgrade - How to get a smaller footprint!!!' project by 'Tada 3D printing (see ) and ran into a problem with my go-to Prusa Jet Black PETG filament.  For some reason it wasn't sticking to the bed plate regardless of settings, and was producing very surfaces - almost like very coarse sandpaper.  I'm pretty experienced (I have a Flashforge Creator Pro II IDEX machine, and am a long-time owner of a Prusa Mk3S+), so I don't think it was me, and my new Mk4 has been running perfectly for some time now.

Eventually I replaced the Prusa PETG roll with a brand-new roll of Sunlo PETG, and immediately started getting the print results I expected.  So, I'm pretty sure the Prusa filament had degraded over time (I don't do a lot of volume or large part printing).  Is PETG susceptible to long-term degradation or hygroscopic effects?  

I attached a photo of the roll if anyone is interested.  It has an ID number that ends in '31.7.2022' which looks like it might represent 31 July 2022, so that would make it almost exactly two years old.