This is odd, but items that aren't reachable are being added to the count. For instance, I have no mushrooms that are reachable by any path, but they are in my edible list. Same with slime, Reed fibers, algae, and a couple of other things. some of it isn't even visible in the game. I've attached my save if that will help.
Just look at what is available verses what you can get to. A lot of it is in storage containers. For instance, I have approximately 4300KG of algae, but it says I have closer to 5t.