The way someone says your name can change without changing a single letter.

Names carry tone, and tone is the part that shifts. The same word can be said warmly for years and then start arriving flat, careful or clipped, and you notice at once without being able to point at anything you could quote. That is real information rather than imagination, though on its own it proves nothing. Something changed, and the letters cannot tell you what.

If you have heard it, ask plainly and without accusation whether things are all right between you. Give the person room to say no. And when you are the one who has cooled, remember they can hear it.