SymbioteSynapse

Depends where you live. I live in a desert so humidity isn’t an issue, but dust is. I keep most of my filament in bags just to protect from dust. The only one I actually vacuum seal is tpu. Pla, pla+, and petg all do fine without. If I store it for more than a year though, I run it through the dryer first. Or at least have the dryer running while I print from it.

Make sure you calibrate your e-steps after swapping hotends. I did the same thing on my ender 3 putting on a volcano hotend, and started getting overextrusion. After adjusting the e-steps it was back to normal.

Check for a partial clog. 80% of the time i get that consistency with petg, its because the nozzle is partially clogged. The other 20% is the ptfe tubing is shot. Usually it partially melts and causes underextrusion.

Wet filament could be an issue too, but this is pretty extreme for wet filament.