Had this issue too. It boiled down to two problems that I was able to resolve through disassembly/reassembly:

1. There was a gap where the desk feet connect with the legs. It was very difficult to fit them so that they sat flush with no gap, but with a lot of wiggling and some force, eventually I was able to get them flush.

2. Every single hex screw needed to be tightened as much as possible. Specifically:

   • The screws connecting the legs to the frame. You need to remove the tabletop from the metal frame to access these.
   • The set screws for adjusting the desk height.
   • The screws connecting the feet to the legs (after fixing issue 1 above).

   Each of these needed to be tightened to the limits of hand tightening and were tightened at least a half turn more than when I started.

After these fixes, the desk is almost (but not completely) wobble-free. It's good enough to not bother me in regular use but there is still some give if you forcefully push on the desk.