When creating an event on the calendar app for mailbox.org I can see the participants in the event details and whether they have accepted. I can also see this in Right Calendar.
However if I create the event on Right Calendar I can't see the participants in mailbox.org unless I edit the event.
I tested with ETAR and the participants shows up either way. I have included the screenshots from mailbox.org
When creating an event on the calendar app for mailbox.org I can see the participants in the event details and whether they have accepted. I can also see this in Right Calendar.
However if I create the event on Right Calendar I can't see the participants in mailbox.org unless I edit the event.
I tested with ETAR and the participants shows up either way. I have included the screenshots from mailbox.org