ERG mode stopped working with TR app on my elite nero

The erg mode stopped working with my Elite Nero rollers earlier this week (TR support, see minute 27 of Capitan workout on 2023-09-20). I use the iPad app.

Resistance mode still seems to work fine.
Using a garmin structured workout to control the trainer seems to work fine.

I’ve tried (with no success):

  1. Uninstalling the app and reinstalling
  2. Shutting down the ipad and trying again
  3. Using the TR app on my iPhone.
  4. Checked that the TR app was open only on a single device at a time.

Garmin was (and is normally) powered off.
Software (TR app and iOS) is all up to date.
Firmware on the Nero is also up to date.

(tried to send an email to support, but I get this: