Yes, it works without any additional plugins (like the experimental Gutenberg plugin). It sounds like you may be combining scripts, which can cause them to load out of order. Some core WordPress scripts ( like wp.a11y (accessibility) requires it to load in a specific order. Are you doing any type of javascript combining, minification, etc.?
I have tested in a fresh install with only Gutenberg and Surecart installed.
Okay we will take a look. Just a heads-up, Gutenberg plugin is a beta plugin, so it’s not stable. It’s not required to use the block editor and SureCart. Here’s part of the description from their plugin description:
Are you a tech-savvy early adopter who likes testing bleeding-edge and experimental features, and isn’t afraid to tinker with features that are still in active development? If so, this beta plugin gives you access to the latest Gutenberg features for block and full site editing, as well as a peek into what’s to come.