That is very odd seeing the “H” in “The” having a different font and boldness compared to the rest of the text, if everything else is set correctly with the font, size and boldness like you said, have you tried just highlighting the letter “H” and changing the text, size and boldness to the same settings? Perhaps it can pinpoint what is the font its currently using in that H. If not, try closing the program and maybe restart your computer. Then reopen the application to see if it goes back to normal if its set as its supposed to be originally. Hope it helps!