Proxy object could not be cloned error when saving form - intermittent

[TouchstoneIQ]

Having an issue, it's hard to narrow down between InertiaJS and form builder but it only happens in form builder when we specifically edit formStepControls in the builder to change the label of the 'final' button. If we do not change that label, the form saves. If I do edit that label, we throw a dom exception. I'm not calling it a bug just yet, it's a weird behavior and we've not seen it before. I think the error is happening in Inertia but if I don't touch the finish button label, I can save the form repeatedly and indefinitely.

[adamberecz]

Interesting. No idea at this point. Let me know if you come across any other clues and I can have a look at it.