So I did pre-intermediate N3 -> intermediate N3 and both had explanations for each new grammar point, but going into pre-advanced N2 now it only gives me the terms and skips to arranging sentences. Is this supposed to happen?
These do not yet exist - they take a huge amount of time to write up, check, and implement. I hope that we can start getting the first few lessons of N2 around summertime!
If you really want something else for grammar, you can either read a Guide or check out Bunpro, which is what I have primarily used for grammar. I generally prefer Renshuu question types though, but Bunpro is a good choice for N2+ stuff.
I like to look for native lessons (fully in Japanese). You can usually search "[Expression] + 文法" and find a few good ones. I find video lessons in particular to be very helpful.
