Player are unable to enter Whimsydale or port there
It used to be that when a Whimsydale portal was created you could invite players into your game and they could enter the zone.
This was changed so that now only players that were in your game session at the time the Whimsydale portal was created may enter it.
The change was made due to players / bots goblin farming, looking for the rare mob that drops the cosmic wings and, having found her, selling spots in the party to kill her for IRL money.
So, if the players that can’t zone in weren’t in your game when the portal was created, this isn’t a bug.
I was suspecting that. I guess they just changed that on the Switch cause last season that didn’t apply.