TBH,
You don't really want water on the sides of the tub - it runs down / or drips on the eggs from the top. It should only condense out if the tub walls are cooler than the air inside. Inside a dialed in incubator that shouldn't happen idealy. As long as the temps are right and you can see freestanding water in the vermiculite ( I mix mine drier than that to be honest - mine clumps if you squeeze a handful but breaks apart easily with no water running out ).
Does the cover fit tightly with the press and seal?