I have not. Let me see if I can recreate it. I don't have a steam deck but I do have the itch app on Macbook.
What is your OS? PC? Or are you also Mac?
Viewing post in Belle Automata: Chronicle I is now released! comments
Sorry for the delayed response. I started testing my other itch io games on deck, and they weren't working either. Did some research and apparently the itch io app isn't fully Linux compatible - which is why only the demo was loading and some of my other itch games weren't working either even though they worked on my computer. I figured out how to work around the incompatibility though by working off Reddit.
A bit annoyed with the itch app, but so far no more problems playing Belle Automata. Thanks so much for your help and looking forward to playing your other games:)