One of my messages was duplicated. This is how it showed up on the report:
https://www.etsy.com/messages/1158555957,Ka,2022-08-29,09:57:24,--,--,no
I did respond to another message regarding the same matter. This needs to be corrected.
Nothing needs to be corrected. That's how the system works. You need to reply to ALL messages or mark them as spam. Try marking the duplicate message as spam. You won't get the star this month, but your score should go back up within a couple of days.
@2021Rabbits: The Star Seller metric is that the FIRST message of a NEW thread must be replied to (or marked as spam) within 24 hours. Subsequent messages from the same account (a buyer may have multiple accounts) are supposed to be combined into a single thread.
Help Requests always start a new thread. By the way, if you are creating a custom listing based on a new thread, you still need to reply to the message. Etsy is now putting a blue text warning / advisory on those messages they consider to be a "new message".
At least for the time being, it appears that marking an unanswered message as SPAM (even after the 24 hour deadline has passed) will cause your reply percentage to change in a day or two if the original message was within the current star seller period. But be aware that doing so may cause you to miss other messages from that account.
If you have not yet done so, you might want to read https://help.etsy.com/hc/en-us/articles/4403058372503-How-to-Become-a-Star-Seller?segment=selling
Marking a message as spam just puts that message in your spam folder. You will still get future messages from that person. You have to go to the trouble of reporting a message to Etsy before it will affect future messages.