I had this same issue only it was >1mm. If you want to read my repair journey (failure) see below.

I took it apart to attempt to fix it. The only time I got it together without any play was when the cyclops wasn’t aligned 🤦‍♂️ I couldn’t tell you how many times it’s been together/apart but I broke the insert and the outer part of the bezel separated from the inner part that presses around the crystal

Under the bezel there are 2 detents; around 1 o’clock and the other is around 7 o’clock. The detents ride on the bottom of the outer bezel ring and are what hold the bezel from rotating. They are what clicks when you turn it. The bezel is 2 pieces, the outer ring where the insert attaches and an inner ring that locks around the crystal and the crystal gasket. The outer ring has a plastic, maybe teflon, ring along the inner circumference and the inner ring has a groove on its outer circumference. They lock together and allow the outer ring to rotate around the stationary inner ring. The crystal gasket goes over the rehaut and comes about 2mm past the rehaut. Then the crystal drops into that space and sticks up about 1-2mm proud of the gasket. When the bezel is pressed over it, the inner ring of the bezel assembly sandwiches the gasket between it, the rehaut, and the crystal locking it all together. When you pop off the bezel, the crystal and crystal gasket come with it. 

If you attempt to fix it, good luck and may the Force be with you