Imported functions are not visible outside?

Hi,

I have two files A and B.

% file A
addin_class = NET.addAssembly(addin_path);
automation_class = NET.addAssembly(automation_path);
support_class = NET.addAssembly(support_path);
import PrincetonInstruments.LightField.AddIns.*;

% file B
% Here I would like to use one of the imported functions

With Matlab 2014 this worked. Now I upgraded to Matlab2019 B, but seems like the imported functions are not visible in file B.

Any idea how to fix this?