Can manual notes created via the 'pencil' icon be deleted?

Something went wrong when I copied and pasted a manual note using the ‘pencil’ icon, which becomes darker once a note is created.
I deleted all the visible text inside the text box, but the “pencil” icon remains darker, showing that there is still a note.
Any solutions please?

@Doris_Loh this does not seem to occur on my end. Have you refreshed the page? Does the paper appear listed when using the Notes filter in the right-hand side column? Have you tried the same with other papers? Let me know.

@vicente Apparently, it only pertains to that one paper where I can’t get rid of the bolded pencil after deleting everything visible. I tested with other papers and the pencil icon returns to normal shading after deletion of note contents.