Hello Todd,
I nudged the plugin developer, Daniel Iser to respond back to you. Apparently he hasn’t.
I am only a consultant, not the person managing your site. Therefore, you are at liberty to entirely ignore my recommendations if you wish.
If I was managing this site, here is what I would do:
1) If the site is in production, make a clone and move it onto a local developer site for testing.
2) Attempt to isolate the source of the problem by simplifying the site setup. That begins by deactivating all plugins except Popup Maker.
3) Examine the front end of the site to determine if the problem resolves. If it does, that indicates that a plugin is responsible for the issue you reported earlier.
4) Systematically reactivate plugins one-by-one until the problem reoccurs. That would tell me which plugin might be the source of the issue.
Work systematically and carefully to evaluate possible sources that may contribute to the problem. You are a detective here. Collect data. Systematically eliminate possibilities that may be causing the problem.
That’s the best advice I can offer without having control of the site myself.