Version: 3.1.1-RC1
Delphi: 10.2 Tokyo

In the readme is the new registration for custom serializers descriped as
Changed! Custom Types Serializer must be registered by media-type only, without charset definition (e.g. just application/json and not application/json;charset=utf-8)

I want to add some custom type handlers, but it seems to be broken.
How to reproduce:

• Open up the renders_spring4d_nullable sample
• compile and run
• open the URL localhost:8080/api/parent/1
• Exception EMVCSerializationException will be raised

Since the registration is:

... the serializer do not found them.
When I backport the registration to BuildContentType('application/json', 'utf-8') it works again.