BKOOL ANT+ pairing issue?

I have used both BKOOL and Zwift PC and iPhone apps successfully for the last few years with my BKOOL Pro 1 trainer, but in the last few days Zwift will not pair via ANT+ to the BKOOL turbo trainer.

This is strange and I have tried 2 different PC’s, fresh installs of Zwift and even bought a new ANT+ dongle. The result is that both PC’s/dongles will connect to the trainer via ANT+ fine in the BKOOL app and also both apps connect to my ANT+ HR strap. Zwift will connect to the trainer via Bluetooth but then it is not a Controller which is less preferable. I can not make Zwift pair with the trainer via ANT+.

Has something changed about the Zwift app and is anyone else having the same issue?