You could try the opposite angle with German - watch movies and shows in German, no subtitles. Maybe start with something aimed at children. Sprinkle in some Dutch to mix it up. It can be useful in real-world situations, depending on region.
These passive approaches don't work at all. I tried this with Portuguese, French (which I don't consider learnt at all), and German as well.
Before I took a good teacher's classes, I had been listening German radio for 2 years, learned nothing of substance.
Portuguese, which I do speak, probably even at B2, is the language that I learned through radio, thanks to similarities to Italian and Spanish, and in which I feel the least confident. All my progress with it was when I was actually using it -- spoken or written, looking up dictionaries.
I think YMMV here. If you watch a movie without subtitles, you are sort of forced to pick up understanding, or you won't get anything out of it. This is maybe not the best way to get started, but it helped me getting to a fluent level when talking to people, specifically the "listening and understanding" part. Before, I could read and write (horribly, but legibly, mostly), but would very often draw a blank when it came to understanding what people said.
or have subtitles in German at first. Also helps if you repeat some catch phrases aloud. Especially fun if you're watching together with someone.
One cool effect is that your vocabulary can be heavily concentrated on what you're watching. Like police procedures. (in Alte they speak very clear German, can recommend.)
The only case for me, when subtitles helped, was watching British TV series, first without subtitles, then with them, and improving listening. But only after all the grammatical heavy lifting.
