Hi.
When i inspect the code in Chrome, in the editor in WordPress, i get this message below (by the way, i use MAMP 3.3.0 for my localhost):
react-dom.min.82e21c65.js:110 ReferenceError: isSelected is not defined
at edit (index.js?1c2d:58)
at yh (react-dom.min.82e21c65.js:95)
at lg (react-dom.min.82e21c65.js:120)
at mg (react-dom.min.82e21c65.js:120)
at gc (react-dom.min.82e21c65.js:127)
at vb (react-dom.min.82e21c65.js:126)
at ub (react-dom.min.82e21c65.js:126)
at wg (react-dom.min.82e21c65.js:137)
at Ze (react-dom.min.82e21c65.js:41)
bg @ react-dom.min.82e21c65.js:110
react-dom.min.82e21c65.js:110 Error: Minified React error #130; visit https://reactjs.org/docs/error-decoder.html?invariant=130&args%5B%5D=undefined&args%5B%5D= for the full message or use the non-minified dev environment for full errors and additional helpful warnings.
at Sg (react-dom.min.82e21c65.js:142)
at m (react-dom.min.82e21c65.js:12)
at ed (react-dom.min.82e21c65.js:65)
at If (react-dom.min.82e21c65.js:82)
at v (react-dom.min.82e21c65.js:84)
at react-dom.min.82e21c65.js:88
at rd (react-dom.min.82e21c65.js:91)
at O (react-dom.min.82e21c65.js:90)
at yh (react-dom.min.82e21c65.js:104)
at lg (react-dom.min.82e21c65.js:120)