I have two images, one is the Strava / zPower power file, the other is my SRM. Speed/power lines are the same for zPower so the power line in Strava should be identical to my SRM speed line. However you can see how as the fluid warms up the resistance increases significantly.
My 220-234 SRM watt intervals showed up as about (I used Strava’s “click a segment to get avg power etc so it’s not quite as precise”) 173-191 zPower watts.
I understand this is a known issue, I just wanted to put the images out there so you can see how they compare to what you’re finding. This is the first time I actually saw and experienced the “distortion”. Before I wasn’t paying enough attention to see it.
Graph from it here