"Id #": item()?['Title'],
There may be info about this, but I was unable to find it, so just thought I'd share.
If anyone knows where this information is provided, please let me know, so I'll know where to look the next time.
"Also noted that the issue appears if you have a "." period as part of the Column Title in the Excel file. So I would image that this potentially happens for some other non-alpha numeric characters and also possibly when the column in the compose does not match up with the column in the Excel file."
Thank you @Ms-PowerRanger2!
I was struggling with this exact problem for a few days. I removed the # in the header name as you suggested and the problem went away!
Thank you, thank you, thank you! And Merry Christmas 🙂