After a few days of Connection drops running Zwift on Windows (nothing changed on my setup) I finally seem to have solved it. Read the summary at the bottom! Not all steps are necessary
- Swear and scream at the injustice of it all
- Repeat step 2 for as many times as necessary to feel morally superior
- Re-install Windows 10
- Re-install Zwift
- Re-install Zwift companion
- Sit in your pain cave late at night turning pedals by hand
- Revisit steps 1) and 2)
- Go to bed
- Wait for ethernet cable to arrive now that you don’t trust WiFi
- Excitedly plug in ethernet cable and marvel at internet speeds
- See step 6) closely followed by steps 1) 2) and 8)
- Excessively clean the kitchen (might not be part of the fix but helped)
- Wait for Bluetooth adaptor to arrive
- Research alternative virtual apps (Rouvy and so on)
- With an almost inevitable weariness plug-in Bluetooth adaptor
- Spend some of your Saturday night turning pedals by hand
- Keep waiting for a connection drop that NEVER HAPPENS…
- Get kit out for a proper test on Sunday
- Go to bed like it is Christmas Eve
- Wake up, wait for family to go to IKEA and do this test ride!
- Pray this isn’t a coincidence…
In summary. I think the ANT+ was overloaded (I was broadcasting my HR from my GARMIN watch on ANT+ and connecting my Flux 2 also on ANT+) and so leaving the GARMIN on ANT+ and switching the trainer to BT seems to have helped. None of the other steps (ethernet, re-installs, cleaning kitchen) seem to make any difference.
Good luck
Rich