I think you should create a support request for this. I also get a bunch of browser console errors when using the feedback widget.
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://feedback-static.mendix.com/feedback.css. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).
445ms html2canvas: Unable to load stylesheet TypeError: "NetworkError when attempting to fetch resource." mxui.js:79:49236
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://feedback-static.mendix.com/feedback.css. (Reason: CORS request did not succeed).
750ms html2canvas: DOMException: "CSSStyleDeclaration.setProperty: Can't set properties on CSSFontFaceRule declarations"