When changing port dimensions nothing changes on the model

I can see the length and width but what is 4.63" ???? The height is 16", if I change it, the value reverts.

Speaking of, the transparent panel does the same thing on every setting change so you need to go check and uncheck the box every time. I'd store the settings as variables then reset them on page changes at the end of your script. 

All I wanted to use this for was to figure the proper port length to reach a desired frequency. The max dimensions I want are no more than 18" x 18" x 42" , preferably smaller but that's the space I have to work with. The inconsistency of the app makes me doubt the accuracy. 

Just ran again, now the port measures 16.5 x 3.54 x (I assume 40") , Check the last pic with the close up of the port. None of the numbers are correct but two may be considered close enough.