I started having this issue late November last year and have now gotten it fully resolved with the help of both Elite's and Zwift's tech support.
After all the checks with firmware and diagnostics different apps, a new board etc, the issue was found to be dried grease and lint buildup on the motor screw.
This was causing the motor to stutter and not position magnets correctly. Here's the link to my full post on my case and fix on the Zwift forums..
https://forums.zwift.com/t/erg-workout- ... /562842/18
Hope this helps
mark539 wrote:March 2023 - I am experiencing difficulties with direto XR in Erg mode using Zwift. The trainer sets resistance very high and does not drop resistance as I exceed target. For example with target 195W resitance, i am hitting 300+W at around 60rpm and there is no change from the trainer. In such a circumstance as the target increases, say to 240W, the trainer increases resistance, at which point I am unable to sustain that power output.
BTW I am using Apple TV and Zwift, so this is not the Zwift Windows problems reported in January.
I contacted support and elite have shared this set of checks for people. I have completed these checks and there is no problem reported by the checks.
May I ask you to make a couple of checks to better understand if there is something wrong?
Please could you please make the following test to better check what is wrong?
From My E-Training app go to Workouts -> Level Mode (it is a free function so you don't need an active annual subscription)
Click on Start and while you are pedalling change the level from 1 to 16 and check if you feel the resistance variation.
Moreover with the help of the video of this link:
Resistance Check On Interactive Trainers: https://elitesrl.zendesk.com/hc/en-us/articles/360014596239-Resistance-Check-On-Interactive-Trainers?source=search
please take a video of the internal motor while you power on the trainer (start the video with trainer powered off) and a video of the stepping motor while you are changing progressively the resistance levels from My E-Training from 1 to 16 and from 16 to 1.