Hello Lawrence,
The frx file type is exported automatically whenever a UserForm module is exported. The frx file contains information about the position and type of controls used on the UserForm. If I had known that this was for a Mac, I could have told you the macro would bomb. There are many tools available to PC users that the Mac doesn't support. You should update your profile to reflect which OS and version(s) of Excel you use.
After looking at the code, I see your ListBoxes use the Change event, which is the default event. This is most likely causing the problem. I changed this these to Click events since you are checking the Selected property, there is a possible processing lag between the Change and when the Click is recognized by the system. Here are the macros with a few changes made. Try this out and let me know the results.
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