Plugin is causing issues in Gutenberg editor

When this plugin is enabled on our site, it’s causing this weird issue with saving – basically, if you make any edits to a page, it reloads the page during the save/autosave and any changes you made are gone. Disabling this plugin resolves the issues. We have the latest version of the plugin, WordPress, and I’ve double-checked the items in the pinned post at the top of this support forum.

JS console shows the following relevant messages:

HubSpot plugin – IntegratedAppEmbedder initializing for: {
“app”: “integrated-plugin-proxy”,
“baseUrl”: “https://app.hubspot.com”,
“route”: “https://app.hubspot.com/integrated-plugin-proxy/7881635?integration=wordpress”
} console.js:32

HubSpot plugin – IntegratedAppEmbedder send StartApp message for: integrated-plugin-proxy console.js:32

Uncaught (in promise)
Object { code: "invalid_json", message: "The response is not a valid JSON response." }
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code: "invalid_json"
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message: "The response is not a valid JSON response."
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: Object { … }
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defineGetter: function defineGetter()
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defineSetter: function defineSetter()
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lookupGetter: function lookupGetter()
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lookupSetter: function lookupSetter()
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proto:
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constructor: function Object()
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hasOwnProperty: function hasOwnProperty()
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isPrototypeOf: function isPrototypeOf()
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propertyIsEnumerable: function propertyIsEnumerable()
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toLocaleString: function toLocaleString()
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toString: function toString()
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valueOf: function valueOf()
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: function proto()
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: function proto()