"you have mail" change in FreeBSD 11

This isn't a very important thing, but I haven't seen it mentioned yet, so here goes.
Over the last couple of weeks I have noticed that the "you have mail" notification in the shell (/bin/sh in this case) has changed in FreeBSD 11. It used to be (in all earlier releases) that you could get back to a shell which had been inactive for some minutes (ten?) and press enter, and the shell would say "you have mail" if you pressed enter (if the user has mail, of course).

Well, in FreeBSD 11, it is not enough to press enter - you will have to enter a command (like ls or something), if you simply press enter you only get a new line.
I only have upgrade two machines to FreeBSD 11.0-stable yet, but both shows this behavior.
Machine one
root@kg-v7# uname -a
FreeBSD kg-v7.kg4.no 11.0-STABLE FreeBSD 11.0-STABLE #0 r307729: Fri Oct 21 22:34:13 CEST 2016
     root@kg-v7.kg4.no:/usr/obj/usr/src/sys/GENERIC  amd64
machine two
root@kg-u35jc# uname -a
FreeBSD kg-u35jc.kg4.no 11.0-STABLE FreeBSD 11.0-STABLE #0 r307748: Sun Oct 23 19:17:49 CEST 2016
     root@kg-u35jc.kg4.no:/usr/obj/usr/src/sys/GENERIC  amd64
Has anybody else seen this?
The MAIL variable is correctly set, too:
root@kg-v7# echo $MAIL
Not sure what is going on here.
I also notice that, when I have two terminals open, if I read my mail in one, the second will still report that I have mail until I do something in that terminal.