The only thing I can think of is that the fel house was placed by a dummy character who was not in any guild so the house sign would bear a certain name. That character has since been deleted. The tram house character who placed the home is still there and in the guild. Since houses are owned by accounts, not characters, I am not sure why this would matter... any thoughts?
since the FEL owner was deleted and wasn't in a guild.
alliance members won't be able to use it.
your co-owners and friends can, because they are on those lists.
in order for the alliance and guild settings to work
you will have to get one of your other characters as owner.
maybe Mesanna could help you with that
or you can transfer that house to another account
then wait a week and transfer back.
(my husband had issues like this once and that was what we had to do)
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you can step onto the tram teleporter, because they are alliance members.
and since the fel side is open to the public, thats why they can go there.
but they can't step back on, because they aren't alliance to the character who placed the house.