Tacx Flux firmware 3.3.40/1.1.6

With the latest firmware version on board (3.3.40/1.1.6) I’m experiencing huge resistance fluctuations when riding ascents in RGT Cycling. Works fine in Zwift.

If it helps at all I’m using an iPad/iPhone combination connecting via Bluetooth. 

Could someone look into this please, or provide a previous firmware version?