NO Overtime pay if Vacation Days Used

In Austin, Texas we used to be paid overtime even if we
used vacation time during that work week.

We were told this was eliminated to bring Austin in line
with other plants.

U.S. labor laws do allow this. They also allow reducing
pay to a minimum wage.

I'm curious whether some other plants still are paid
overtime in weeks that include vacation time or sick time pay.

Management argues that it is proper and legal.
Minimum wage is also "proper and legal".
Is a pay reduction next?