Crape myrtles don't usually "die back" in winter in Georgia. If they had to resprout back from the ground this spring then clearly they are having issues.

And they are "dwarf"; what is the maximum size per the industry for these?

Yes it is a true dwarf. The mature height is listed a 3-5 ft.
My friend got a bunch of them from on an line nursery, as replacement plants from a company she uses online. She had to many and shared two with me. She said hers are growing well. They were very, very small when I got them. Maybe that's why they didn't do well the first winter, I don't know. They do look like they are struggling. When I looked it up - I believe mine is cherry Razzle Dazzle - it said it is deciduous and 3 ft tall - 4 ft wide. I will try to post a photo soon. Thanks again.

Every single Razzle Dazzle series I've tried has died if it's small. They only seem to survive if planted when a larger size.