I've got a 2020 Telluride SX that, from the very first day, had a persistent minor (but very irritating) rattle coming from the headliner at the climate control/dome light console between the front and 2nd row seats. I had the dealer try to fix it twice under warranty and they replaced the roof mounted console but that did not solve the problem. I finally decided to remove the climate control/dome light console myself, which I did with plastic auto trim tools, I gently pried the console away from the headliner starting at the back. When removing it, the metal clips on the rear and side get bent and you will need to bend them back into a U shape before reinstalling.
I found that there is a plastic ring around the headliner opening that is glued to the headliner and that the glue had failed and the plastic ring was loose everywhere except at the front edge. This appeared to be rattling against the headliner. I used E6000 glue (https://eclecticproducts.com/product/e6000-craft/
) to glue the plastic ring back to the headliner, clamped the joints with C clamps and vice grips (you don't need to clamp very tightly, just enough to press the plastic ring down onto the headliner). I then let it cure for 24 hours and reinstalled the climate control/dome light console. When reinstalling I carefully examined the plastic ring where the consoles metal clips were and noted that those areas of the plastic ring have a shelf that the metal clips have to snap over. I then used needle nosed pliers to bend and shape the consoles metal clips into a flattened U shape and pressed the console back into the headliner. Where the clips were (which I had marked with masking tape) I used a small screwdriver inserted between the console and the headliner and pressed upwards on the metal clip until it snapped over the shelf on the plastic ring.
This appears to finally have fixed the rattle problem, but it only took two failed trips to the dealer and almost 2 years before I figured out how to fix this problem.
Here's another thread on the same problem and there's some photos of someone who did the same fix. Sorry I didn't take photos before I reinstalled the console into the headliner.