This happened to my 2017 Z71. Actually started making the clunking noise when I got it back from the dealership. They were replacing the headliner because of a rear window leak and had my truck during the holidays. It was so bad I thought someone took it on a joyride and thrashed it. Here’s a pic of their write up, hope it helps.
FYI the springs still sounds creaky like an old truck but according to this forum it’s something that happens when it’s below freezing. So I’ll wait until it warms up before complaining