App Designer packaging standalone desktop app - MAC

Let me start out by restating that I'm on MATLAB 2020a on a MAC computer.

I have an app that I've designed in MATLAB saved in an .mlapp file:

myapp.mlapp

When I package it for a standalone desktop app (runtime installed from the web), it saves as a .app file. That file runs fine on my computer one time. After that, my computer give an error that it "can't be opened", even if I remove the app, etc. This also happens if I upload the .app file to be shared via Box or other similar sharing software. Whoever downloads it can't open the file. Has anyone seen anything like this before? Is there some setting I can adjust on the output of app designer on a MAC that will create a .dmg file instead of a .app zipped file that seems to be quite finicky?

Open to any suggestions/thoughts!