Yes I could reorganize / lower the number of shares so that they are on a higher level in the directorytrees but that means that I cannot use the webgui to arrange (different) access + acls on the lower (sub-directory levels). I prefer to use the WebGUI over the CLI for that. Also more shares mean that you can accommodate finetuned shares over SMB / NFS etc for the users in my family.
Apart from that the problem did not occur in the past when I had the same number of shares. So my question is (regardless of the number of shares) what is causing this, and how can I still make it work.
If OMV5 is allowing only a limited number of shared folders, that's in fact OK, but I have not read this somewhere, so I would guess that I could use this facility even if I would create many more shares. (Which I do not intend to do. )