Joystick movement Problems

I have a Sanwa JLF joystick and while i was playing today i started to notice a bit of resistance that quickly turned to a lot of resistance when i move it. thankfully it doesn’t stick it just feels really hard to move. This is the second time something like this has happened. last time i just ignored it for like a week and it seemingly fixed itself but now that it’s happened again I’m a little concerned. If anyone could give me a hand i would appreciate it