Environment: Windows 10 20H2 (also saw with 1909, did not try on 2004), v3.16.0. Using only with Logitech Harmony at this point, two hubs. Both hubs have static IPs.
Issue: Start Home Remote app, all Harmony Activities shown, but the currently-active one is shown as “Off”.
Workaround: Can be corrected by going into Settings, picking the associated hub from the Devices list, then clicking the Save icon (no other changes/actions). Every time the app is closed and opened again, this needs to be repeated.