Apartments are not under auto demo.

It’s not possible to transfer servers without having demolished your apartment.

The only way you are “supposed” to lose an apartment is by demolishing it yourself.

The only reason I can come up with as to why you think you had one but no longer do, is:

1. It was an alt you bought the apartment with. (Or dreamed it like someone else said, which to me is intense.)
2. There is some kind of bug. Try contacting a GM using your previous name. Honestly that’s shouldn’t have been the issue as characters have special tags. This is why when you transfer after being “Eternally Bound” the bonding and friendslist and everything else remains in tact.

So only logical answer is you bought an apartment with another character?