I'm currently watching the first season of this wonderful series! It was released a couple of years ago. I recently found out about and purchased season 1 (2018) and have just ordered season 2 (2020).
It's region locked. I'm in the U.S., but I was so intent on watching that I bought an unlocked Blu-Ray player just for this!
So far, it is amazing, both in visuals, and in story. Fans of WW2 U-Boot adventures will not be disappointed!
One quirk I found, though. I have to select the Dolby Atmos audio. There are sections of the dialogue that are not subtitled. If you select the first audio choice (Dolby 5.1) they will be in German or French. If you select the second audio choice (Dolby Atmos), the non-subtitled dialogues are spoken in English, apparently by the actual actors, not by an overdub!
https://en.wikipedia.org/wiki/Das_Boot_(TV_series)