I have THE solution !
Install firefox and the rtc player will worke like apparently apple have done an other time a feature and not a bug whith safari...
For calendar, prefer sabre.io at apple calendar like this you could do proper injection inside them in PHP ( a possibilty in apple few years ago....but a feature now, and not a bug too)
lanoux
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution