Open tool in Guide GUI app won't run uigetfile

I've compiled an application for Matlab that, when run and the open tool is selected from the toolbar, is supposed to directthe user to the default location specified in the gui function. This location is a specific directory on one of the stash locations on a network. However, when the program is actually run and the open tool is selected, the dialog box points to the local drive directory instead.

In contrast, this is not an issue when the .m file is run in Matlab as a standalone function. Is there a reason the uigetfile cannot locate the default directory name when run within the application?

[curoi]

Also, a second uigetdir command in the same callback function does not even run after I attempt to select the correct directory in the first uigetdir command.

The following command also inexplicably returns an empty array despite the dirpath location being specified and ending in '\':

filedir = dir([dirpath, '*.jpg']);

[Jan]

Please use the chance to edit the original question instead of appending a comment.

Use fullfile instead, because it considers trailing file separators:

dir(fullfile(dirpath, '*.jpg'));