Im using thunderbird with a nextcloud calendar Nextcloud v25.0.3 Thunderbird v91.13.1 DAVx (to sync on Android) All my calendars sync across the devices and Ive added my caldav calendars to my mobile devices. When I try send an invite, from Thunderbird, to someone else in our organisation to accept on their mobile, the invitation sends an email with 2 attachments 'invite.vcs' or invite.ics' So there is no option to accept or decline, if I open the attachment the only option I have is to save to calendar, but that will also not send an accept or decline. If I send the email to another address, for example a gmail address, the inivite sends exactly how you would expect and has the accept or decline buttons. If I send an invite from my mobile device to thunderbird, the invitation sends as expect. But once I try accept or decline in thunderbird, no response seems to be sent back to my mobile device or atleast nothing i can see If I send from mobile device to mobile device, there is an option to accept, which opens a browser window, but atleast the option is there. It also has an attachment, this is 'event.ics' So I think the issue is somewhere with thunderbird, but Im not sure. Would really appreciate any help