Property [$isCachingForms] not found on component

Inside a widget I get "Property [$isCachingForms] not found on component".
https://flareapp.io/share/w5BngJX5

I'm confused, because I can't find this in the documentation.

Flare

Property [$isCachingForms] not found on component: [app.filament.resources.customer-resource.widgets.invoices] - The error occurred at http://localhost/customers/1