I am having issues with my Tacx Flux S, where the resistance will suddenly spike during ERG workouts. It can be perfectly fine for 20-30 mins, then it will all of a sudden add a load of resistance.
Yesterday, I did a interval session where the first two sets went smoothly. I did the hard efforts as normal and dropped one gear for the easy bits. When the third set started I could barely pedal the thing during the “off” parts of the set. I had to drop to my easiest gear, but was still pushing almost 250 watts at 30 rpm :-s
I am using an up to date Flux S (4 months old) and the latest version of Zwift on my MacBook Pro. Everything is connected through Bluetooth.