they works for me. Problem could be that You have NO reflection probe in front of mirror, or You are judging it in the viewport and You have low viewport setting in preferences. Read that page about probes I posted earlier. It is pretty easy to understand how they works.
Also do not expect perfect reflections - You will not have them in TM now. They are just fake.
See images and their description. Play with reflections´probes and your viewport and export probes resolution settings.
It has to work as or me I think
All the best