Linux vs NetBSD NIS passwords

[KC9UDX]

Thank you for replying. I don't have an opportunity to verify everything at the moment. But I can add this:
The server has a GENERIC kernel, i386, 9.2.
There is only a primary server at the moment (for months). The only secondary server is being rebuilt and won't be done soon.
All UIDs for NIS users are in the range 1000..1099
The password map is really exported; I have had Solaris and NetBSD clients using it with no issue. Currently there is only 3 NetBSD clients and 8 Linux clients. The NetBSD clients work without a hitch. The Linux ones (OSMC, Debian, Raspbian, and Manjaro) work for hosts. I can verify that all maps work on NetBSD, but I'll have to see again exactly what ypcat reveals in Linux.
The Linux clients (none of the clients actually) have no LAN hostnames in /etc/hosts.
The Linux clients were configured in the minimum way as recommended in the Debian instructions. (Can't say exactly what that is at the moment).

I will have to double-check the Linux configuration again.

There are no indications of errors in dmesg or elsewhere, except maybe ypcat.