It shouldn't be related to size. What is the wiki, and what is the page you are using to search for it? Please give links not just names.
Where have you tried to search it on? Saying "FandomMobile" doesn't explain it.
Is this the Fandom App? If so, only selected wikis are included.
FandomMobile is not the app, it's a browser version for mobile.
Oh... So how can my wiki become a selected wiki?
Is there some process it has to go through?
What do you think?