Unusual Nozzle Clog

I have been using my Ender-3 V3 Plus for several months without issue, but the last couple weeks I have been running into a very weird clogging issue. I will print out the first layer of a print and then clog the nozzle. It will essentially stop the filament from heating up at all. I cannot extrude anything, even when I turn the temp up to 300. The filament will break off at the very end of the nozzle so that I can’t even pull out or push it through to clear it. I replaced the hot end of my printer, which worked for a single print before I ran into the same issue again. Does anyone know why the filament wouldn’t heat up? I have touched the nozzle, and it is extremely hot, so I don’t understand why the filament would not melt. I am using PETG, but I have not run into this issue before. Does anyone know a solution? or a way to unlog nozzles that are full of filament?

Not a whole lot of information to go on here.

a) Nozzle type & size (0.2mm, 0.4mm, 0.6mm, etc)
b) Filament brand

Can you physically push the filament through while pulling back the release switch? Could be your extruder gear is ground up and has no grip left. I’m not too familiar with the V3 Plus, but it’s somewhat similar to the KE. I know on the KE it has a little screw on the right hand side that is accessible if you remove the outer shell, this allows me to tighten or loosen the extruder gear for stronger or weaker grip on the filament.

Being hot to the touch and being the correct temperature for printing aren’t really the same thing, when you replaced your hotend, did you transfer over the original thermocouple, it’s possible it’s not sensing the temperature correctly?