370z possible rear suspension issue

[Henryz34]

I have a 2017 370z base model, with minor suspension mods as follows: 20mm spacers all around, Swift lowering springs, and rear camber arms.

There seems to be a small suspension issue in the rear. Whenever maneuvering at low speeds or reversing, the rear right wheel feels as if its going over a bump, even if the path is perfectly level.

Something feels loose or uneven, even though everything is torqued down tight. There is a minor clunking noise that occasionally happens along with the uneven bump feeling. Sounds like a deep clunking noise.

Any ideas as to what the problem is and how to fix it?