@Sudha – I cannot say exactly, but maybe it's the special character <FEFF> for index entries or XML tags (or something else entirely).
You can detect <FEFF> with a TEXT search (not with a GREP search!), just type in
in your "Find what:" field.
Oh, and what do you mean exactly by: "moving the anchor"?
Thank you so much.
I can replace that character by <FEFF>. Now working fine for me.