Add the 'order by' column to the end of each select (i.e., display the field myiT.Unique_ID) and see what happens.
It appears that because the second query is using an alias which bears the same name as a field in one of the tables, it is ignoring the prefix in the order by and using the alias field instead.
It is almost as if SQL is taking the order by field name, looking to see if it appears in the select list first, and only when it can't find it, checks the prefixed table.
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It is by the Beans of Java that thoughts acquire speed,
the hands acquire shaking, the shaking becomes a warning.
It is by caffeine alone I set my mind in motion.