A nickname can feel like affection to the speaker and confinement to its owner.

A shortened name or a teasing label can feel warm to the person using it and like a small cage to the person wearing it, especially when it fixes them to a version of themselves they have outgrown. Affection and confinement are not mutually exclusive, and the speaker rarely sees the second one.

Use the name people give you rather than the one you have made up for them, and take it seriously the first time someone asks for a change. If a name you carry no longer fits, you are allowed to say so plainly, and most people will simply adjust.