Some suggestions for the OP:
If running Windows on your computer, download the EPOS Connect application and check to see if there is a firmware update for your BTD 800. There have been a number of updates for the BTD 800 that was supplied with my (now old) ConnectClip. Some updates were to fix issues with applications like Teams or Zoom.
If running Windows, you might consider downloading and installing Genie 2 and use the device updater to check the firmware version of your ConnectClip. If not current, then use Genie 2 to update the ConnectClip firmware. My ConnectClip was updated some time ago by my hearing aid provider when we called Oticon Tech support as I was having problems connecting to my iMac desktop. The support person suggested the the Sennheiser (now EPOS) dongle always be used with any desktop as many Bluetooth implementations had bugs or profile issues that prevented correct operation with the ConnectClip. The person allowed that laptop implementations of Bluetooth were usually OK for the ConnectClip but not always. My work MacBook Pro works fine with my ConnectClip with the built-in Bluetooth 4.2.
Using the BTD 800 with my desktop allows my ConnectClip to reliably work when it is paired and connected to the BTD 800. I have not turned off the internal Bluetooth for the computer as it uses Bluetooth for the mouse and keyboard. If you don’t use other Bluetooth devices with your computer, you might be able to turn off or disable the internal Bluetooth if your computer has it. I would then forget all pairings at the ConnectClip and then pair with the hearing aids and then pair the ConnectClip with the BTD 800.
I have not paired my iPhone 12 (mini) with my ConnectClip as streaming and calls from the phone work fine with my OPN S 1 aids (firmware 8).
Good luck,
Stuart