No notification emails are sent if mentioned in file comments

⚠️ This issue respects the following points: ⚠️ • This is a bug, not a question or a configuration/webserver/proxy issue. • This issue is not already reported on Github _(I've searched it)_. • Nextcloud Server is up to date. See [Maintenance and Release Schedule]( for supported versions. • I agree to follow Nextcloud's [Code of Conduct]( Bug description No notification is sent when a comment on a file is posted with a personal notification. In the activity (web frontend) the comment is mentioned. Thus, it is detected correctly by the server. Only the immediate sending of mails is not done. The delayed sending of the mails is not affected. Other mails can also be sent. So, the problem is not related to the mailing system. Steps to reproduce 1. Set the personal notifications to send mails on comments on files. ![image]( 2. Also, set the notifications for email reminders for unhandled notifications ![image]( 3. Prepare anothe…