Saving in Textedit without special characters

My Mac OS system is Ventura 13.6.3. I'm trying to submit a file saved in Textedit to a software program that rejects the file because it contains "special characters." In the saving process I see squares in front of most of the words; characters that I did not put there and are invisible in the saved document. I assume these are the "special characters." I am saving plain text .txt format. How do I get rid of the "special characters?" They appear after the first word in a list of unique words. Attached is a screen shot of what I am seeing.