FWIW...
I don`t have ceiling tiles, but two modified sky lights above my HT rack system in the living room..
And with their plastic grate light diffusers they would rattle, so what method worked very well for me, and, not only was inexpensive, but super easy and quick to install, was to buy a couple of sheets of pre punched peel and stick self adhesive felt pads..
I then simply lifted the diffusers and stuck the felt pads in the corners and every foot or so, on the wooden dress frame that the diffuser`s rested on..
All rattles gone..
All open to listening room, Kitchen cabinet doors had the same treatment.
Also, though probably more expensive, shallow in height, peel & stick rubbery material bumpers could be used as well.
In my case I chose to use those only on all wall mounted pictures in my house for buzzing, and rattle mitigation with excellent results.
Good luck with whatever method you choose.
Kind regards, OKB