Detection of new objects in argument handling fails
The symptom is
#1237305720: Argument "newBlog": Querying the repository for the specified object was not successful.
When looking closer it turns out that on the first error all is well, but when submitting a second time, the exception is thrown. The reason is, that we rely on a new object to not have an UUID. But with the resolution of #3477 all entities get an UUID upon creation - boom.