No Signal for Heartrate Monitor and Erg Mode Intermittent

Hi all,
at my wits end…
I started having trouble connecting my heartrate monitor via the Companion App.
Set is new August 2020 Kickr Snap, current model Apple TV, and iPhone 11 with Zwift Companion App. Since new everything has been working well, a bit of trouble with erg most often, but turning the bike off and back on normally fixed that and erg would re-activete.
Seemed to coincide with the latest CA release. I have since spent hours trying to resolve the issue - to the point of: Updating the iPhone iOS, deleting all apps on the iphone and re-installing them, removing all other possible connections to Bluetooth HR, Updating the Apple TV, deleting and reinstalling Zwift on the Apple TV and still it wont connect.
The Power, Cadence and Controller all connect via the Companion App okay, by HR still will not connect until I turn off ‘Pair with Companion App’. Then, it allows me to connect the HR, and seems like all other signals to the trainer are maintaned, but then Erg mode wont work.
Erg mode will only work if I connect via companion app and don’t bother about the Heartrate monitor.
But - the results are sometimes intermittent with ERG mode.
I have read lots of support topics, gone back through and re-connected everything from scratch.
I don’t know what else I can try…
Pleeeease help meeeee!!