MBP 2016 - BigSur - BTE issue

Hi guys, I’m having big issues since a few weeks with Zwift on MBP BigSur OS.
I‘m using kickr v5 and BTE pairing.
Pairing itself is ok however when riding in Zwift the resistance does not match the track I’m riding.
Uphill gets easy, flat is hard.
Must be device specific as it’s fine on an iPhone.

Any idea on what the route course is and how to solve.
Already tried uninstall, debug of BT.

BT of other devices is turned off


Yes I’m using built in BTW with MacBook Pro 2016 (2.9 dual core i5) and MacOS BigSur
I tried the mentioned bt tricks but it was not successful. Connecting devices via companion app seems to be fine.

I found BT connection to be laggy and intermittent on my MacBook Pro, so just got a cheap Ant+ dongle off Amazon. Been solid ever since. Not a fix if you need to use BT but if you can use Ant it’s much better.

Cheers Charlie - to you question. Why do you think one would need to use BT ? A+ is always an option isn’t it ? (As long as usb input is available)

I tried BT as my Direto and HRM had it. But it was laggy and the trainer didn’t run smooth. Ant+ has been stable. I think a lot use BT as it’s built in and Ant+ requires a separate purchase. I paid £6 for a dongle off Amazon rather than any branded one. Plug & play.