Unfortunately I don’t have a Windows machine at hand, so unable to test/try to reproduce your issue. It depends a bit through which method you’ve installed Specter, but you need to make sure that it runs with the –hwibridge flag.
Perhaps also ask your question in the Specter telegram group.
Btw, is there a specific reason you’d like to connect through the HWI-bridge method? As mentioned in this thread, by far the easiest way is to just run Specter only locally and connect to your node through Tor.