Joining a rider doesn't work

Hi. Yesterday I was taking part of a group ride and my ant+ stick got disconnected. Had to restart zwift, and in order to get back to that group ride I tried to join one rider I follow who happened to be in that ride too, but it did not work. Restarted zwift again, tried to join another rider, and did not work either!!! So this feature clearly is not working.
Then rode solo the same course of the group ride but in reverse direction, hoping to find then and then turn around and join them, but I could not find them. It was early in the ride, so they must have been riding when I went looking for them. How is that possible??? Seems like another bug.

I don’t think you can join a rider that is part of the event. You need to rejoin the event if it has late start enabled.

Thank you Gerrie.
Yes the event has late joining enabled (and coincidentally I joined it late yesterday and also on monday of last week). But there was no option to re-join the event when I had to restart zwift due to that connection problem.

Late join is only active for the first 30 min, can it be that 30 minutes has passed.

If the event is set to show only event riders, then you will not be able to see them while free riding.

I’ve late joined racers (not the race itself) by waiting for them and sprinting like h-e-l-l to catch draft. Easiest in multi-lap races, esp. volcano laps. You can see them and draft. but, since you are not actually in event, they can’t see you or draft you.And even if you finish ahead of them, you will not be in any results.

Thank you for all your answers.
Yeah it was more than 30 minutes after event start when I had to restart, so it is understandable that I could not rejoin the event.
And yeah I think event riders do not see other riders, so that explains why I could not find them.
Anyway, I think zwift should be smart enough to allow a rider who has been dumped from a ride to rejoin the ride by joining a rider who is taking part of the ride.