Resistance Slipping

Please help! Ive been using Zwift with Tacx Flux S and ipad set up for at least a couple of years. In the last few months I’m experiencing the resistance constantly dropping in and out. Its only for a few seconds but the power can drop up to 50% before picking up again.

It happens with ERG on or off
Ive tried disabling everything else nearby (watch, phone, partner’s Tacx, removed bettery from my foot pod)
I calibrate regularly in the Tacx app
When i tried a training plan in the Tacx app it just disconnected after a few minutes every tike i attempted it.

Does anyone have any ideas? It’s making Zwift practically unusable unless i want to do a very low resistance ride.
Garmin customer support haven’t been hugely helpful.
Is my turbo doomed for the scrap heap or am I missing something obvious.