I recently opened the Polish films and series category, there are very few in it. I searched the Internet and I was shown a lot that should be on Netflix, but I can't find them on Netflix.
Netflix generally only has a few films from the overall picture. What exactly is your question?
How I find the one I found on the Internet that should be on Netflix or if at all
Was the language in which the Polish films were available?
If there's no German subtitle / German synchro, then you have to change the language in the settings. Most of the time there's English, then you have to put your Netflix completely in English.
I understand Polish, but I don't find it
Have you ever changed the language in the settings? To do this, go to "Account", then to your profile name and there under Language to "Change" and either enter English or Polish and look again.
And are you sure that where you watched it was about Netflix Germany?
365 days is from Poland
There's no real list of Netflix films on the Internet. Above all, Netflix keeps throwing out films that are still on Internet lists. If you have Netflix, you will hardly be able to avoid looking for the individual film directly.