DIAGNOSIS: The metal tray itself is rigid, but the plastic brackets that hold it to the desktop can flex or the screws can work loose over time, especially if you've loaded it up with heavy power strips.
FIX: Let's secure it from the top. 1) Clear everything out of the tray. 2) You'll need to access the screws that go through the desktop into the tray brackets. They're under the desktop surface. 3) Using the provided Allen key, check each screw (usually 4 or 6) and tighten them a quarter-turn. Don't crank them down hard, as you could strip the threads in the bracket.
IF THAT DIDN'T WORK: If the tray itself is bent (less likely), or the brackets are cracked, Uplift will send you replacement parts for free. Just take a picture and reach out to their customer service—they're good about this.
HEADS UP: Be mindful of the weight you put in that tray. It's designed for cable routing, not as a shelf for heavy battery backups or multiple laptop power bricks. Distribute heavy items towards the ends, near the support brackets.