Trying to find posts isn't working either.
All of my posts in there are hidden, search results referring it are hidden, etc. literally anything that would allow me to get in there is hidden
I just ran into this. I was looking for the Nick Fuentes thread, and a search showed no such thing.
Turns out there is a thing to the side in the search area that said "Show Ignored Content". Once I clicked that, the Nick Fuentes thread showed, and I was able to go to it and click Unignore.
So, you might be able to do it that way. However, I'm not sure if the search will show a whole forum. It might only show threads and posts.
I'd like it if my profile included a list of things I have ignored. Maybe this does exist, but I haven't found it.
Edit: I found it ! Go to your account, and go to Account Details. On the left side of this page is a menu bar, and Ignoring is the bottom item. Click the Ignoring button, and you can see all the people, forums, and threads you have set to ignore. This is on a laptop. The Mobile interface might be different, but it should be accessible in a similar location.