Yeah LA and Miami are kind of the obvious answers, as early sunbelt cities which have kind of reached the point of stability/being built out.
There are quite a few southern cities which are "sunbelt" in the sense that they're largely new growth cities and aren't very walkable, but aren't growing particularly fast. Though Jackson, MS, Macon, GA, and Columbia, SC aren't what people usually think of when the term comes up.
I wouldn’t put Miami in the same category as LA – the city proper, Broward, and Palm Beach all had double-digit growth rates during the 2010s and even Dade still grew by 8.2%.
To answer the question, maybe also parts of the Bay Area depending how far you want to stretch the term Sun Belt?