Webdatarocks content disappear after clicked apply in field toolbar, then apply button in Fields disable

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webdatarocks content disappear after clicked apply in Fields toolbar. Appreciate someone could help. Thanks

error can reproduce same as link below. https://www.webdatarocks.com/demos/javascript-pivot-grid-demo/

It seems that they released new 1.4.2 version a day ago - https://www.npmjs.com/package/webdatarocks. Have you tried it?