Can you confirm that you are still running main firmware 2.02, as shown in the M122 listing in your first post?

I can ask chrishamm to look into this message, but he will probably ask you to upgrade to Duet Web Control 2.0.0-RC6, available at https://github.com/chrishamm/DuetWebControl/releases.

Thank you so much for your quick reply, that fixed everything!