I've updated the two nodes to what they should be, /etc/pve/.members is now displaying:
"01": { "id": 1, "online": 0},
"02": { "id": 2, "online": 0},
"03": { "id": 3, "online": 0},
"04": { "id": 4, "online": 1, "ip": "192.168.8.14"},
"05": { "id": 5, "online": 0},
"07": { "id": 7...