Everything in my example data is 5 by 1, including
ChannelGainUN = [1.1:.1:1.5]' , so it was all compatible and successfully ran. I just made up the data so I could check that there were no syntax errors and that ir ran successfully. You should be able to duplicate my results.
I presume that you have or will obtain actual input data which you want to use. Of course, you should make the dimensions of everything compatible. You can make adjustments to my program as needed to match your data and problem.