Umap maps are no longer editable

Hi everybody,
I created a umap a few weeks ago (Clavariaceen RLP - uMap) and was constantly editing it.

Yesterday, the “Edit”-pencil was present, but upon saving, the system said there ist a system update ongoing and the maps are readonly. Today, the “Edit”-pencil is gone.
I tried to open the map with the “anonymous-edit” URL, but this is only displaying a white page with the latest Firefox. In Edge, It shows a HTTP 403 Error.

Is this a known issue?
Has anything changed how umap works?
Is this only my problem, or is it general?
Is there anything I can do about?

Thanks for your help!

Wolfgang Prüfert