Location of Schema used for current xml file unclear

I am working with a standard that has quite a few revisions of its Schema: AUTOSAR (autosar.org)

When opening an ARXML file in XML Notepad the tool shows me the auto completion and does on-the-fly verification.
However, it is not clear to me which exact schemal version i.e. xsd file XML Notepad is using: While I see one version in the View/Schemas... dialog, this is sometimes clearly not the revision of the schema that is used internally: the two schema revisions have different elements, and I get elements in the auto-completion for my xml file that are not present in the schema revision that is indicated in the View/Schemas dialog).

Is XML Notepad buffering schemas in the background, or pulling them from the registry or something like this? If yes, what is the logic behind this?

In particular it would be good if XML Notepad would support the following use cases:
(1) I want to provide XML Notepad with the exact schema file I want to use when editing an xml file.
(2) I want to have an indication somewhere in the program of which exact schema file is currently being using.

Thank you for this tool. I have been using it for years, and I am generally very happy with it. However, the schema issue described keeps giving me trouble.

The report points to the View/Schemas dialog, schema resolution, auto-completion, and on-the-fly verification; no source files or tests are named. Start by tracing how XML Notepad selects the schema for an ARXML document. Done means the requested schema can be supplied explicitly and the exact active schema file is visible to users.