`man` cannot find any entry

[J C <jcurt312%gmail.com@localhost>]

I'm new to NetBSD. I recently installed NetBSD and found that `man`
cannot find any of the entries:

>>> man man
man: no entry for man in the manual.
[root@localhost ~] #
>>> man 1 intro
man: no entry for intro in the manual.
[root@localhost ~] #
>>> grep _default </etc/man.conf
_default       /usr/{share,X11R7,pkg,local}/man/
[root@localhost ~] #
>>> echo $MANPATH
/root/install/share/man:/root/install/share/man:
[root@localhost ~] #
>>> find /usr/share/man -type f | wc
   19885   19885  730129
[root@localhost ~] #
>>> uname -a
NetBSD localhost 9.1 NetBSD 9.1 (GENERIC) #0: Sun Oct 18 19:24:30 UTC
2020  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC
amd64


However, `man -k <keyword>` does work.

Any idea how I can fix this?