In my experience of trying to join many a group ride yes, 95% of the time you should u turn around again immediately as zwift puts you in the wrong direction in watopia. Richond course thursday or friday has no u-turn and you will see how quick people can be off the list
When you get put on the zwift course (watopia) check all the names in the rider list. This can take upto five seconds so don’t pedal too fast as zwift may make you turn around. If the person is not on the list and zwift makes you turn that might be the correct direction.
Have a bit more time?, pre watch the person before you join and see if it’s forward or reverse you need to be on.
Lost them while on course ? use the phone app select rider profile and fan view and see where they are on course.
As for group rides, read teamup.com for direction and ride slow till they catch you.