I wouldn’t worry about what the edge tells you. It just realised you did something you hadn’t done in a while. It might not have been the TSS, but that you rode up a hill at higher power than usual.
I always have a litrle laugh when I make mine say “3 days” or whatever. For me it happens when I switch between my watch and my bike computer without syncing - like when I haven’t synced the watch for a while, but then use it for a harder ride, it’ll say 3 days because it doesn’t know if the other rides I’ve recorded on the bike edge. (I think it does know once it syncs to Garmin Connect, but I’m not 100% about it)