Did you recalibrate everything? I find that usually solves any issues I have with power discrepancies between units.

Just the PT. I always top off right to 100psi before a ride too. But yeah, I should double check the Tacx. Also, I could recalibrate on the 935. Haven’t connected that yet, since I like the twist mount on my 910, and that has funky cal settings.

My vortex was very inaccurate, and the offset changed with temperature. That being said it was never a problem because I had a powertap and used trainer road power match to use the powertap.

Building my PT into a new Flo60 and I don’t want to burn up a tubeless tire on the trainer.... but yes, I’m doing TrainerRoad

I also had a Vortex that I used (several years ago) with P1 pedals. The Vortex was wildly inaccurate with swings as much as 40w, depending on duration of use (heat in the unit), tire pressures, etc. A one-hour TrainerRoad session would basically have two totally different 'characters' depending on how warm the Vortex got. The more watts I needed to produce in something like a VO2 max or sprint interval, the worse the Vortex performed. I tried fans, outdoor use, etc.... it was also inaccurate.

I finally threw the whole thing away and moved to a trio: Elite Drivo, Elite e-Motion B+ rollers, and a Cyclops Fluid 2 (portable). All three are significantly more accurate and stable. I have cross calibrated/checked all with a combination of P1 pedals and a Quarq Dzero.

I can echo this. The Vortex was also very jerky besides the ultimate sins of both extreme inaccuracy and consistency. Like JRT_Racing bailed on it. My gf and I are now indoor training on a Tacx Neo with a combination of SRM, Vector 3, Neo Power data. I can watch each of those and see accuracy and consistency. Plus it is easy to use. The Vortex was finicky for me.

My vortex wasn't jerky but it did have the variable offset issue that grew especially with harder intervals. The problem I had with this was when trainer road changed their power match algorithm to match the offset at the end of the previous interval. The vortex would cool off during a low intensity recovery interval and the offset would shrink so it would way overshoot at the start of the next interval. In vo2 intervals when I should have been hitting 380 watts or so it would sometimes start upwards of 420, which needless to say made things pretty difficult.

I also eventually got rid of it because of these issues and got a neo, which has been a revelation. That being said I used the vortex for two years and got quite good results with it, and at the time the price was definitely right.