UIAxis corrupting plot - OK in Axis

I have an app that plots data correctly using figure + axis, but when incorporated such that the same funcion is passed UIAxis (from app designer) the plot is corrupted.

The first image below shows the correct response - there are 10 "channels" of vertical data, then a gap = 10%, then another 10 channels, etc.. This has worked/been in use for a few weeks and still works as designed. The input to the top plot is from code:

                fig = figure('Name','My Figure'); 
                ax = subplot(1,1,1);

The second image below is the same data as above with the exception of sending the plotting function a UIAxis from App Designer. The data width stretching is NOT desired and/or coded in. Unclear how to stop this response in UIAxis?

[Geoff Hayes]

@Marc Elpel - you may need to show more of your code so that we can get an idea of how you are plotting the data. Or provide a small working example that exhibits this behaviour.