Aren't they the same? Just enter one.
No, they are not the same. Different amounts.
An RRB-1099-R is retirement entered in the 1099-R interview.
An RRB-1099 is equivalent to Social Security entered in the Social Security interview.
So sounds like they should enter both? They came on the same sheet?
Yes, That is common for RRB forms - retirement distributions and the railroad equivalent of Social Security are both sent at the same time.