Old Elite trainer, now sending only constant power (but receiving slope input correctly)

I have a 2015 Elite Real Turbo Muin, which I’ve used happily on Zwift since the beta days…

Recently I’ve had various connection problems, which I initially thought was related to a new Windows laptop, or an old ANT+ dongle, and problems were intermittent.

Now problems seem constant, regardless of old laptop or new, old ANT+ dongle or new. I’m able to connect, and when I am pedaling in the Paired Devices screen, my power reading changes appropriately. However, whenever I move over to start to ride, only a single power level is being sent continuously (i.e. my avatar rides endlessly at 200W, or 170W, or whatever power I happened to be pedaling at the moment of leaving the Paired Devices screen).

But communication is still happening! The trainer’s resistance changes appropriately, and on-time (in my experience), with Zwift course climbs and descents. It all feels normal. But either the trainer is sending, or Zwift is receiving, this constant power message.

I started by asking Elite for support, and they said to ask you… Any idea if this could possibly be a Zwift problem? (I’d love to, of course, not replace the expensive trainer, even knowing that it is five years old…)

Thanks for any thoughts, suggestions, or recommendations.

Hi, has anyone else had a problem with this and did it get resolved? I am having the exact same issue with my Real Turbo Muin.

Will upgrading to the FE-C software help this? I have been trying to resolve this for a while now, going backwards and forwards between Zwift and Elite