do you have a small white ptfe tube that sits on top of the nozzle, and guide the filament through the hot end ?
If not fit one.
I think you said you got one with the machine but there wasn't one in the hotend when you took it a part.
There probably should have been one in the hotend from day one.
You might have had your plastic feed tube pushed down far enough tht it could print. That might have moved.
The ptfe tube is a good idea anyway :-)