Are those theads setting properly?
Luiz, to me this looks like it is not sealing and the pipe Dope liquid really doesn’t do much better than PFTE tape.
I have had better luck staying with plastic 100% or metal 100% until the final fitting used to connect the shutoff valve.
The PFTE tape should be “chewed up” when you put on the fitting, if not the 2 different sizes are not sealing and may very well leak.
I have seen this same thing when folks use electrical couplings for pipe (they are not tapered like normal pipe couplings) and they started leaking after the walls were closed.