Firefox browser error displaying NETFLIX subtitles

Hi everyone. Firefox displays the wrong size of subtitles when watching movies on NETFLIX. The inscriptions are so tiny almost invisible. I changed the subtitle display settings on NETFLIX, but it didn’t work.

Maybe this:

This is not the solution to my problem.

Same problem with Manjaro XFCE desktop. Manjaro (same Manjaro and computer different desktop) Gnomedesktop, Firefox subtitles not a problem. I use Google Chrome which is usable in XFCE and subtitles are usable.

The problem is a combination of XFCE and Firefox on Manjaro Linux on my computer. Linux mint and Mate desktop on another computer Firefox subs are OK.