After 2 days I found the solution; from the layout as defined in my question, I have a Spinner which is bound with a custom TextView:

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/listTextViewSpinner"
    ...
    android:textSize="@dimen/spinner_list_item_text_size"
    ... />

Here, I have an extracted dimension resource: @dimen/spinner_list_item_text_size.

This has been defined…