The reason is likely that you edited the log to include the FTF tag. It can take a long time for a log edit to be detected especially if there is no now logs. The last log was on the date of the FTF so it is likely that the edit was after that
Information about data update from the FAQ
How up-to-date is the data?
Normally the data is 24-36 hours behind. But there are circumstances that will take a longer time to detect. What is detected within the given time frame is new found (or equivalent depending on cache type) logs. Deleted/edited logs might take a longer time. Adopting of caches or changing of status (disabled/archived) might also take a longer time to detect. So how long time will it take then?
That depends, if the cache in question gets a found log, everything else should sync up as well. Otherwise it takes up to 30 days for a non archived cache and up to 90 days for an archived one. The more precise time depends on a lot of factors, including the age of the cache.
If your finds seems to be out of sync, you can use our self-support system to tell the system to go through your data. You find it by clicking the orange support button that are available in the top right on most pages.
You can refresh a cache in support/selfe support. I did it and it is now recognized as a FTF