Hmm.. never heard of such a mechanism for the game. Houses yes, but FC's themselves should remain regardless or else the game would have notified you.

my best bet is this:

The members there dispanded it
They kicked you and rebranded the FC under a new name,
or maybe it was changed and you were kicked on accident.

Best bet is to contact your Previous mates and asked them what happened or if you can search them on lodestone see if they are in an FC