Unable to import CSV file into photoshop

Looking for some help and sorry about the long post.

I am trying to do a variable data merge in photoshop to import the photos (individual & team) plus names into a template.

I have had no issues doing this in the past, but now I keep getting an error:

Could not parse the file contents as a data set. The name 'a' is not a variable in the current document.

I had different column names when I started, but have dumbed it down to a, b, c for both my csv file and psd file. No spaces, everything matches, etc.

No matter what I do, I keep getting the error.

I have shut down and restarted the program, my entire computer, uninstalled and reinstalled photoshop and I still get nowhere.

I have tried different templates, used ChatGPT and went through all of what it said to try. After 4 hours of trying everything under the sun...I'm about to give up and manually do Memory Mates and Buttons for 300 orders.

Does anyone have any ideas?