[Bug] Last relationship in Monsters doesn't get saved

[tabacitu]

Bug report

What I did

I'm on the use-create-recursively CRUD branch, and testing on the Demo #348 These each will get merged to 4.2. so I expect the problem to be there too.

In Monsters, tried to fill in the last relationship field (with everything inferred), but that didn't work:

No idea if it's an error in the demo or in CRUD.

What I expected to happen

Save

What happened

Not save

What I've already tried to fix it

Nothing

Is it a bug in the latest version of Backpack?

After I run composer update backpack/crud the bug... is it still there?

Backpack, Laravel, PHP, DB version

When I run php artisan backpack:version the output is: