Hi!
This post is more informational as I’ve already figured out the issue.
After swapping my hotend to a 0.6 nozzle for a vasemode, I wanted to go back to 0.4 and to preserve the 0.6 in working condition, I used a spare complete prebuilt hotend that I got with my printer - this was two days ago.
Ever since I started getting clogs in my extruder when printing PLA. Things were better with PETG, but I needed to print something in PLA and I couldn’t even get it started or print for more than 3-5 minutes before getting a clog.
I took apart the extruder probably 10 times in the past two days until this morning, each time to remove a clog. I had to even cut the PFTE tubing a couple of times with it, shortening it just so I can remove the clogs - which led me to replacing the PFTE tubing too.
The cogs of the extruder seemed always in good condition and I only print PLA and PETG. - I got a spare extruder but I wasn’t ready to give up on a perfectly looking one.
The issue was a heat creep that was caused most likely by a faulty ceramic heater/thermistor in the prebuilt or maybe poor thermal paste application - the extruder was always hotter to the touch than the hotend when I disassembled it.
If you need to get a clog out of the extruder, check the bambu wiki page as there are unlisted YT videos showing you how to open it.
After replacing the heater+thermistor with new parts, everything works smoothly, printing continuously for 12 hours and still going.