Strange snmpd issue with 6.7

I am running OpenBSD 6.7 and am having a strange issue with snmpd(8).

The issue is that it doesn't have all the arp entries but this was
working before. I don't know exactly when this started happening
but I just noticed today.

Here is the machine in question and what I get:

wharrels@styx1:/home/wharrels$ uname -a
OpenBSD styx1 6.7 GENERIC.MP#3 amd64

wharrels@styx1:/home/wharrels$ arp -a | wc -l
985

Box is acting as a firewall so that is normal. Actually normal to
have many more than that. But if I do a query from another machine
via snmpwalk I get a completely different number of machines in
the arp table:

[wharrels@newtron ~]$ snmpwalk -v2c -c public styx1 ip.ipNetToMediaTable.ipNetToMediaEntry.ipNetToMediaPhysAddress | wc -l
456

Not even close to the same number of machines. The above OID translates to
1.3.6.1.2.1.4.22.1.2 if you want to try this and see what you get.

Should I be using a different OID to get the arp table or is there
another way to do this? It might be that this was not working quite
right before but I don't remember it being off like this.

Any help would be appreciated, thanks.

Winfred