Yah yah I know totally first world problem.
But a colleague of mine has started referring to her entire team and now me just by our initials rather than our names. Eg "thanks for doing that AN" rather than for example "thanks for doing that Anna"
I don't have a common name and there is nobody else in the company with my forename (3000+ employees) so it's not like I'm going to get confused with anyone else.
We have a very close working relationship and are quite friendly yet this whole only using initials thing feels really impersonal and offensive to me.
AIBU unreasonable to be offended by this? And should I say something??