Honestly the receptionist calling you by it and the office asking you for it might be a hint that they are not judgy as a practice with you having a preferred name. If the receptionist calls you that every time it means it’s prominent in your file (especially if it’s multiple receptionists).
I’m sorry about that. They suck for it but still might not be doing it out of malice and could be doing it for the same reason as using your old name. If all the other members of the office use your preferred name you probably don’t need to worry. (sorry for the spam of deletions I was trying to get the wording right and not sound like rude or like i’m justifying your doctor misgendering you and using the wrong name)