I've had the Ender 5 Pro, as is, for 3 months.
After I tried a cheap PLA filament (maybe too cheap), it clogged the nozzle. I cleaned it, but any other filament I have would have similar problems from then on. After some days doing test prints, it clogged again. This time, I heated it up to 240 ºC, I unscrew the nozzle, cleaned it up, chopped the Capricorn tube (it had clear symptoms of a previous tube not reaching the bottom of the hotend and leaking material around it), perfectly aligned, cleaned the heating block with a brass brush, started screwing the nozzle… and it never reaches the end. It even jiggles a little bit (by "jiggles", I mean that when the hotend is hot, you can push the nozzle back and forth, and it does move... like it was a joint, and not a threaded bolt), like it was too small for the block. I try screwing a new nozzle. Same happens.
To me it looks like the heating block thread broke, but I can't be sure. I tried a thicker nozzle (0.8 mm, but same thread in the end) and it worked. I could feed filament and it wouldn't look like clogged (at least for 15 cm of feeding filament, when in previous cases it was almost instantaneous).
Time to get a new heating block? Any recommendation?
Would another kind of heating block be better?
Edit: Here's a picture of the bottom of the heating block. Now it's clear there's a metal chip glued with material, and almost (if any) no thread at all.
Another question. Could it have been that cheap material that caused the clogging, or was it just a lack of proper maintenance?