Hello,
this is an attempt to bring attention to this issue Recent calendar app versions break buttons in embedded calendars · Issue #5243 · nextcloud/calendar · GitHub
(in the hope that it gets fixed soon… our public embedded calendar is not usable at the moment)
If you are also affected, leave a 
in the github issue (only comment there if you have something to add, not for “this affects me too”.)
Maybe related? Feature Request: "Impressum" and Privacy Declaration Links - #4 by tcit and the resulting commit fix(Public-Sharing): Show footer with server details and eventual ToS through PublicTemplateResponse by tcitworld · Pull Request #5184 · nextcloud/calendar · GitHub
Thanks for reading!