This morning, I went and tried to apply Antonio's suggested fix to line 22.
It didn't help.
But, furthermore I realized that ndsctl clients is showing "4" but "users=0" is getting passed to the dashboard. I tried modifying lines 21 and 22 of 30_nds_users_usage independently and together. Tried deleting /tmp/nds_clients and running update a few times. Still users=0
Now, 15 minutes later I went to copy/paste it for you and I see that ndsctl clients still says "4" but the checkin string has "users=1"
Antonio, I'll PM you the checkin string.
Seems to me that I was able to affect some improvements when I edited line 77 of 30_nds_users_usage
| if [ "$NDS_IP" == "$LEASE_IP" -a "$NDS_MAC" == "$LEASE_MAC" ]; then