I had a similar issue myself recently, when the problem with the ? appearing occurred I went back to edit the Fields and Text block generating that content and deleted then re-inserted the offending space, and that fixed it.
Could you try that and if it doesn't resolve the problem one of the supporters will investigate further.
I deleted the fields and texts blocks and recreated them. I did fix the problem. I had edited them. I had noticed the question marks there previously and had deleted and recreated previously. I didn't realize it was the editing that caused the question marks to appear. It is fixed now.