Hi Matt,
As far as I could investigate, disabled endpoints are hidden more aggressively in the new Settings UI, and some virtual-audio drivers got tripped during the upgrade. The fastest way to bring back them is to re-enable them from the legacy Sound panel.
Press Win+R, type mmsys.cpl and press Enter. In the Playback tab, right-click in the empty area and turn on "Show Disabled Devices". If you see "Wave Link Stream" and "Wave Link Headset", right-click each one, choose Enable, then set your preferred one as Default. Repeat the same in the Recording tab. Close with OK and test again.
For context only, Microsoft has documented 24H2 audio regressions affecting virtual audio solutions (they called out Voicemeeter specifically). Once your endpoints are re-enabled, Wave Link should behave as before.If they still don't appear, tell me and I'll try to investigate further, any information on errors and such is highly valuable for me. Let me know please!