When trying to connect to the desktop, have you attempted to turn BT off on your phone? Many BT items in the cycling space can only maintain one active BT connection and if you’re paired with your phone sometimes that interferes with desktop.
Are you on the beta or production version? If the beta, are you on the most recent version? A version of the beta got released that killed Bluetooth, but TR released an update the next day that fixed the problem.
If you are on the production version, please reach out to TR support directly