This is not about the size of your repo, or about your Quality Gate conditions.
Let’s take a closer look at the ‘-’ projects. I’ve drawn some boxes of my own on a section of your screenshot:
Both of these projects only have XML in them. AFAIK, code coverage isn’t possible for these projects. So instead of showing 0% (which implies that there could be a higher number) it just shows ‘-’, which you can happily read as “Not Applicable”.
In the other project you have both Java and XML, so coverage > 0 is possible. It looks like you probably need to generate a test coverage report and feed it into anlaysis.