Can’t even match wattage for warmup

Trying to complete a zwift workout (using a kickr snap) never had an issue before today however I am finding it impossible to even get up to 85w for the warmup - it keeps telling me erg disconnected, then re callibrating. The resistance becomes way too high and after 15 seconds goes easy, I then get back up to the required wattage but it eventually just gives out and bugs out. I have researched the spiral of death however I don’t think this applies in my case. Is it something to do with the gears? (Don’t know a thing about them) any help would be appreciated

I’ve experienced similar recently but going the other way in that I go over the warm wattage, but the figures still show in black, here’s a screenshot showing it, I was supposed to be at 58W, the workout plan is build me up lite