What KJ said. The human fingers can feel as small as a 13 nanometer difference in surfaces. If a dial indicator were set up against your cue and the variation measured, what you are feeling would likely be .001" transition or so. If you can barely catch the edge with your fingernail, it might be around .0025". A human hair is usually .0025"- .003".
In addition to finishes shrinking, different ring materials will expand/contract at different rates (changes in climates contributes to this), but they don't "move" in a way that they would ever be "pushed back into place". Cues aren't built that way.