As I've said elsewhere my from factory ACC in my T6.1 MY21 Caravelle does brake to a stop and will auto resume so long as you manually brake when asked.
ACC will hold and display "ACC Ready to Start" for a short while and is fine for the rolling stop start type traffic where you only hold a few seconds.
After that ACC will display a brake symbol. If you brake then (and not before) it will restart - if you don't brake then the brakes release (which is a bit odd)
It becomes very second nature once you get the timing. Restart with Start Stop is straightforward, the engine restarts as the radar sees the traffic move, release the brake and ACC takes over. If you look very carefully the ACC symbol is always lit (at least on my digital dash)