BFletcher
TVWBB Honor Circle
If you don't hear back and since you like it so well maybe you can get lucky (with little trial and error) and find some other branded filter that fits. Some don't show specific dimensions but one of the filters linked below does show the dimensions:
https://www.amazon.com/dp/B0C45Q9N48/?tag=tvwb-20
https://www.amazon.com/dp/B0BC19GGYG/?tag=tvwb-20
https://www.amazon.com/dp/B0C45Q9N48/?tag=tvwb-20
https://www.amazon.com/dp/B0BC19GGYG/?tag=tvwb-20