Hopefully, this will help. I’m also on 8.1. I’ve experienced similar today with another coin’s QT. When I installed QT and upon completing the install, letting the program run from the ‘run now’ tickbox, it presents me with a different address to if I run from the program files icon (and a different level of synchronised). Upon closing the program and relaunching it my address had changed, I thought I’d done something silly, but reinstalling the program and following the tick box presented me with the lost address again. So there are two copies of the wallet, and it would seem one is only accessible when launching after installation. Now, I’m wondering, if you run as administrator, as I had to when installing, does it save the wallet into the elevated account’s roaming appdata? And could this possibly be your issue?
*edit* yes it does, running QT clients from the ‘run as administrator’, lands you in the administrator accounts wallet. I guess that makes sense from a logical point of view, but I’ve not seen it mentioned anywhere before.