Job category and type not customizable on updating entry

I have added a new job via API. Now when i'm trying to update a selected entry it returns an error that the categoryId and employmentId should not have additional properties. The properties have not been changed, therefore the message is somewhat odd to me. Could this be a bug?

When trying to change the categoryId or employmentTypeId to a different id the error also occurs. Is this also a bug or are we not allowed to change the id in hindsight?

"path": ".body.categoryId",
"message": "should NOT have additional properties",
"errorCode": "additionalProperties.openapi.validation"

Thanks