Multiple values in table

I recently upgraded from v9.2.6 to v9.4.3 and I found weird behavior regarding selecting multiple values. If I use the following query with the
Format as Table" option:

  last("field_a") as a,
  last("field_b") as b
FROM "my_measurement" WHERE ("some_tag" = 'some_value') AND ("time" > now() - 20s) 
GROUP BY "some_other_tag"

Different things happen in the versions (using table view):
In v9.2.6: All fields are shown and the alias is used as column name.
In v9.4.3: Only the first (i.e., field a is shown, with the column title “first”.

When did this change and how can I have the old behavior in the new version? Am ?I doing something fundamentally wrong here?

Bonus question: What exactly does the “Format as Table” option do? I understand it produces a table instead of a time-series data, but how exactly?