Am on new PC now running Windows 11 and struggling. My program set-up was done by a professional IT so I'm sure Mozilla/Thunderbird was moved correctly. Started using Thunderbird Friday afternoon with no problems. I get about 150 emails daily to my main address + a few to 2 other addresses. All addresses have this same problem. For years now on Thunderbird with Win 10 and now 11, once I OPEN an email, the listing changes from BOLD to normal print. Believe that's common for email programs. Since just prior to 3 PM yesterday, ALL incoming Emails are still in BOLD after being opened whether replied to or not. Makes it VERY hard to know which ones I need to go back to and read further. I do tags but only for really important things. Does anyone know what might have happened? I have NOT tried to change any settings in Thunderbird. Help please!!!!