I saw your other thread here, New user on mobile app and I’ve seen you said you are a new user.
So I’m going to make this suggestion: Unless you have a good reason that you understand, just use Wikilinks instead of Markdown links. Your life will be so much easier.
For Markdown links, are you showing any examples of links that don’t work? My guess is that you have spaces in some names. They need to be %20 instead of space. If you use Wiki links you won’t have that problem. Honestly, just use [[Wikilinks]]!