Have you tried one of the recommended browsers?
Maybe a microG-issue (?)
https://community.e.foundation/t/list-apps-that-work-or-do-not-work-with-microg
Or some other issue related to G-services required by the app … or blocked trackers (or other Advanced Privacy-feature) (?)
Is that row of numbers an error code? Try contact thd developpers of the app and ask for the meaning of it (?)