Question: very annoying problem in user interface. Losses bracket matching at random locations

I depend alot on bracket matching to help me during writing code.

Maple suddenly losses bracket matching at some lines. I think it related to using strings with "\\" in them.

I make sure I have bracket matching on

I use worksheet mode (corrected), Maple 2020 under windows 10.

I made small video. Notice how the brackets do not match on the second line there.

Do you see how the brackets do not match on that second line there? This movie below shows what happens when I remove "\\string" from the line. Now bracket match starts to work again.

This is a serious problem for me. Any suggestions what to try to fix it and what can cause it?. Once bracket matching is lost, it is lost all the way to the rest of the code below the location where it started to lose first time.

restart;
if length(data_last(k,8))>300 then
   fprintf(file_id,"%s\n","\\footnotesize");
fi;

I think I have to find different editor to use and write the code to .mpl file since I have lots of such code and I need to have bracket matching working.