I didn't see your post until now.I've had this hacked switch for many years but primarily play smash on stock fw, I only prepped my switch by updating to 13.1 to play Pokemon and prep my switch to pkhex pokemon in. I also on the side have decided played a bit of the new AC Update 2.0 + DLC, I didn't pirate any of the software so I'm fairly certain that something on AC got me banned considering Pokemon wasn't out at the time when I was banned.
Theres no convenient way for me to access saves so I just went online with cfw sysnand since I've read from a lot of other places that it was safe as long as you didn't cheat or pirate games.
I gave myself all DIYs, but I think my Island floor tiles were really scuffed that's the only thing I could really think of that would have banned me. I'll be buying a new switch, but I will not be modding ac anymore since I'm terrified of getting banned again.
Did you use map editor in NHSE? I never use map editor and can't speak if it is caused the ban. Beside Dream Suite, there is no known ban for do anything.
Go online with Atmosphere can raise the ban risk that happened to some members. Many are lucky and some aren't lucky. I believe that has something with system that lead Nintendo to detect and the ban prevention isn't completely foolproof, even sometime, it could break.