This is simple deduction. Your site is working perfect then you install a plugin that has many known bugs and new to the marketplace and all the sudden the site isn’t functioning correctly immediately after install or your plugin. It doesn’t take a rocket scientist to figure out what the problem is. By your own admission when we first tried the plugin your comments where that this was a new product and still working out all the bugs. Don’t admit to having a untested product with bugs and turn around and tell the world hey it works on our computer and our website so it must work perfect everywhere else, that is a microsoft fallacy. Sham Sham on you.
Do you have a root knowledge base for customers to work from? If not it looks unprofessional to start out with no guidance or knowledge base
Most support platforms come with a built in root knowledge base for clients to work from and builds over time