yes, Tamino 4.4 has corrected some gaps in the type checking. You seem to be defining an index on all occurrences of “id”? Unfortunately, I do not see teh index definition in your snippets
The issue is that not all the id instances have the same type (in one case anyType, in the other integer), and hence you cannot define an index that contains both. So either define a more specific index (not including both occurrences, but e.g. a separate index for both of them) or make them have the same or a compatible type
I suggest adding the following attribute to your root element:
as Tamino 4.4 has full support for xsi:type, it has to take care that different types possibly being used/referenced via xsi:type have consistent declarations also for their respective child elements. This covers not just the logical schema but also physical properties like index definitions. With the additional attribute above usage of xsi:type is completely forbidden. I hope, that is ok for your application.
It will lead to the same behaviour as in Tamino 4.2 - unfortunately, it is not the default as of XML Schema.
Otherwise you may need to use the block="#all" on a specific element.
Or, simply provide your complete schema with and without the intended modification and I’ll have a look.