Plateaus, and the sensation of plateaus, are extremely normal. I feel them a lot and I’ve been studying every day for over two years! Plus, for reasons mentioned upthread, the sensation of learning doesn’t always match the moments when the brain really is acquiring new information.
When I’m teaching math, I get flaky students like you’d think, but more often, my students are doing better than their brains tell them they’re doing. I think that’s the same with any discipline.
This is also extremely normal. I listened to NHK every day for several months (until those jerks region-locked it 
) and I went a long time without catching a thing. But even getting used to the cadence and the up-and-down of the tones and the raining down of syllables is a legitimate part of your practice. Listening is the hardest sub-skill to fake. I don’t know of any shortcuts or “hacks”; you just have to listen to a whole lot of native speech until your brain starts to organize it.
I’d recommend checking out Japanese-learning podcasts or YouTubers. The Bunpro forums has a really good, new-ish thread about this; I threw in some of my own recommendations too!
I really enjoy Japanese With Noriko. She knows acutely what language acquisition is like and she teaches accordingly. In one episode, she gives two great pieces of advice: work on media that you enjoy, and never compare yourself to others.
My biggest regret of the 25+ years that I’ve studied Japanese is that I didn’t start immersion practice a lot sooner. It’s that frustrating for everyone for the first few dozen hours!
I’d recommend that you not only start immersion practice again but that you build your practice around consuming native content, even if you suck at it. In my opinion, you can start again today! Find something you really enjoy and watch it without English.
I play a lot of untranslated video games too. It took me years to realize that there’s nothing stopping me! You’ll probably still use your dictionary a lot for the first few months, but that really will lessen as the weeks go by. In fact, your success rates in WaniKani will rise noticeably. Seeing a word “in the wild” will make it a lot stronger in your brain and much easier to remember when you’re doing your WaniKani practice!
There are different schools of thought as to whether to rely on Google Translate/DeepL while you’re learning. I personally don’t see anything wrong with it early on, as long as you learn from whatever you type in. I only use it in three cases:
- When I know all the words but can’t piece together the sentence.
- When I think I understand a sentence but I want to double-super-confirm that my understanding is correct.
- As a last resort after checking dictionaries and Googling.
One other tactic that helped me: you’ll start to see words where you’re at at least Guru with the kanji, but the word isn’t in WaniKani. Make your own Anki deck of the ones that you encounter. That’s what I did and it dramatically increased my confidence in my reading ability. I also studied additional kanji; in fact, I recently posted my Anki kanji deck, which you might find useful.
I know this is a lot! You may want to make gradual changes, and you certainly don’t have to follow my advice. I’m nobody special or famous. I minored in Japanese in college but I don’t think that gives me any special credentials. As I said just a few posts up, I’m learning by asking advice, trying new things, and seeing what works, same as you!
TL; DR: Whatever Japanese thing you want to play/read, start today, even if you suck at it.