Measurement on sample tubes in TFTestkit don't match Taylor sample tubes. Which is correct?

I have recently noticed that the 10ml and 25 ml lines on the TFTestkit and Taylor sample tubes do not amount to the same amount of water. I had always used the TFTestkit sample tubes, filling to the appropriate line, then dropping in my speed stir pellet, then testing.

I purchased a Taylor Sample sizer, and it indicates it only works with the Taylor 9198 sample tube. If I add water to the tube, then use the sample sizer, I get exactly 10ml or 25 ml in this tube. If I then pour the contents...

Measurement on sample tubes in TFTestkit don't match Taylor sample tubes. Which is correct?