Why is my concentrate not mixing all the way through the bottle?
First, ensure your sprayer is twisted tightly into place. It needs to be locked onto the bottle before the concentrate will release. And sometimes the concentrate just needs a little nudge in the right direction, so try tilting your bottle if it still hasn't mixed.
Filling your Truman's bottle above the designated line with water can also prevent the concentrate from completely releasing; if you did this, perhaps nudge it in the right direction a little more aggressively :)