Hmmm, looks like something is wrong with the object you sent. If you created this key programatically, then you need to make sure to set the metadata. If you search this forum there's a few fixes around for it, either buy manually modifying the schema or by ensuring your object validates when you first create it.
Did you create the key with a user that is not part of an Organisation? Or the two do not belong to the same org? This will be the source of your issue. Org ID's need to be aligned and the creating user must belong to the same Org. Do not use a super-user.
You need to update the whole object, not selectively. So GET -> Update -> PUT should be your cycle.
If you don't you break the object, and it's links and then break your dashboard.