Wiki pages not showing any more

Wiki pages that I created in Seafile versions prior to 7.1 can no longer be opened. The MD file is still available in the library, but calling it using the Published Libraries function only results in the error message “We’re sorry, but the requested page was not found.”

Example link: https: //www.domain.tld/group/19/wiki/wiki-grundsatz

However, group 19 still exists.
I suspect the problem has been present since I installed version 7.1.5. Before that I was using 7.0.5.

Can you try to republish the library?

Done, but changes nothing.

I have worked in the past with links. It seems that I have change all links. In the markdown editor I have to insert a file instead a link. Right?
After upgrading to version 5 or 6, I had to do this already and it took a few hours. Why do I have to do this again now? I want to write a wiki once, after which it should be usable for years without having to adapt it. I do not understand that.

I had to recreate all links to wiki articles, now the wiki is working again. I am very happy that the pictures were not affected. These still work and I didn’t have to change anything.
I just wonder why I had to do that.