Your power sounds good. Utility service spec is apparently +/- 5%, 228-252 volts for 240v nominal in the US.
I’m also always a little amused when this comes up, was pretty much expecting it when I posted y reply. To add to the fun every AC electric motor nameplate in my shop is marked either 115 or 230v and there’s a reason for that too.
I think the important thing in discussions is everyone understands that when people refer to 220, 230, and 240v they are all referring to the same thing. I usually try to use the same numbers as the OP (or the person I’m talking to.) I did this just a little while ago when a friend called about a problem with his hot tub heater. (we got it debugged and fixed during the call - yay!)
JKJ