Join button not available

I’m not sure if this is a bug or intended behaviour.
When the pop-up appears to join a meet-up, and you click ‘not yet’, are you still supposed to be able to join later?

Since ‘30 minute late join’ feature was introduced, if I don’t join a meet-up when automatically prompted, I don’t get the button to manually join later. I then have to end my ride and start again to join the meet-up.

This is Zwift on OS-X with Companion on iOS.

Occasionally my Join Event button won’t appear when I expect to see it, like within just a few minutes of an event. If I disenroll and immediately reenroll the event via the companion app, the Join Event button pops up right away.