Dragging form fields into a row doesn't work nicely and throws a TypeError

Just tried dragging some fields into a two column row placed inside the form in order to have two fields sit side by side. That didn’t work because when you try dragging a field it grabs the whole form. Then I did it through the inspector which does work, but then the builder became unresponsive.

Found a lot of these in the console:

Suppressing inaccessible window.event undefined TypeError: can't access dead object
    React 2
    g /wp-content/themes/pro/cornerstone/assets/js/app.react18.7.7.10.js:92
    Lodash 2
    Ie /wp-content/themes/pro/cornerstone/assets/js/app.react18.7.7.10.js:24
SyncMessage.js:560:27