Sorry, I was out of town, and couldn’t test anything on my site. Hopefully you will still respond to this.
I did try the Health Check plugin, which shows the site health is good. In Troubleshooting Mode, I activated the theme I was using before when the gallery was working, then enabled Modula with no other plugins active. I still get the same shortcode popping up ([modula id=4966 align=]) and no gallery.