MINUS(ALL) OR EXCEPT not detecting changes in records

Database

MINUS(ALL) OR EXCEPT not detecting changes in records

I'm working on a delta load that should be straight forward.

Day1 Initial - all the qualifying rows from source, loaded into t1

Day2 Delta - all the qualifying rows from source with changes from Day1, loaded into t2

in dev, to simulate change, I modified 2 columns in t2

When I run

(Sel * from t2

MINUS(ALL) / EXCEPT

Sel * from t1)

I'm expecting to see only the records I modified in t2.

Instead, I'm seeing the full result set from t1 with the t2 changes included.

Same results from all 3 functions.

Also strange, when I group all the fields from each table, the outcome is the same.

What am I missing here?