I have a 2015 Silverado 2500HD 4x4 6L90 with 74k miles that is having some transmission issues recently. I am getting really hard shifts from 1-2 and 2-3. It also refused to move in drive once. Hand to put into reverse and then back to drive before it would move. I did notice 1-2 really small metallic items in on the towel I used to wipe the dip stick when I checked the fluid. I had to use a magnifying glass to see them. I purchased this used in 2022. The fluid does not look overly dark nor does it smell burnt. The fluid level may be a bit high as the level shows in the checkered (hot) zone when doing the cold transmission test process. I don't want to try to bring it up to temp to check the level hot. Due to the known issues with these transmissions I do monitor the temp often and it has not exceeded the specified temp since I have had it. My first thought is the torque converter is having issues. Any thoughts before I take it to the dealer? Unfortunately there are no places that rebuild transmissions in my town and many of the third party shops have crappy reviews.