Based on what you've shared, it sounds like there's a leak, and, I don't think it's merely condensation. It would be good to know what section exactly in the seal is leaking. Is it wet in any other spots other than the center brace where the sticker is? So if seal was leaking, perhaps the water is moving down the channel of the brace?
Took these this morning when I woke up after it sat over night with just a tiny bit of water in it. As you can see the wood underneath looks wet in spots along the back and on the far right panel of tank. Just leaving work now, will feel around the base of tank when I get home to see if I can feel a wet spot on outside back of tank or outside right.