First of all thank you very much for the detailed answer!
It gives me ambition not to give up :-)

I'm really new in the field but after dozens of attempts and what you wrote I guess it is a clogged nozzle.

The strange thing is that The printing starts well in all cases and at some point during the printing process the blockage is created (if I understand the situation correctly) and each time at a different stage in each print.


Do you know what can cause blockage during printing? (Fix me if I'm wrong - if the nuzzle was cloged at first I would not be able to print at all .. right?)

I have not tried to print yet with any material other than PLA from the same one spool

Again, thanks for the help!