Link-Sharing always returns error in UI

Dear Seafile-Community,

we’re experiencing an UI bug in Seahub 9.0.4 (Community Edition with MySQL and nginx on Debian 11 behind an reverse proxy) when sending an email to share a link. Independent of whether the mail actually could be sent, the UI always shows:
seahub bug
“Bitte überprüfen Sie die Netzwerkverbindung.” = “Please check your network connectivity”
The call to send-share-link/ returns with status 200 and body {“failed”:[],“success”:[“haas@imbi.uni-heidelberg.de”]}.
Please advise on how to fix. Or is this a known bug that will be fixed in upcoming releases?

Thanks and best regards
Sebastian

As some of our users gave me feedback on this issue I can clarify that this only happens when you try to send a mail for a link of a library. Sharing a link of a folder does not result in faulty behaviour.