The highlighted statement is incorrect:

...confirmed by pressing CTRL-SHIFT-ENTER to activate the array. You will know the array is active when you see curly braces { } appear around your formula. If you do not CTRL-SHIFT-ENTER you will get an error or a clearly incorrect answer. Press F2 on that cell and try again.
You can get the correct result if the formula is not array entered. It depends on what the formula is doing and where the formula is entered relative to the data being referenced.

Try this...

A1:B5 =

X.....22
Z.....37
X.....30
Y.....79
Z.....84

Normally enter this formula in D1:

=MIN(IF(A1:A5="x",B1:B5))

The formula returns the correct result even though it was not array entered.