Modal dialogs are not shown

Hi,
we did recently our log-due update (1.9 → 1.22). So far, most things work fine, but the modal dialogs (e.g. to delete a repo) do not show up:

common-global.js:364 Uncaught Error: no modal for this action
at HTMLButtonElement. (common-global.js:364:13)

The site is behind a reverse proxy. Direct access works.

I noticed that some divs are missing when served via the reverse proxy, so the selector #delete-repo-modal does not find anything.

Is there a special route that I have to forward in the reverse proxy to get this done? Or any other ideas?

Thanks,
Oliver

Can you clean your web browser cache and try again?

That had unfortunatelly no effect.