I have a File/Print/DHCP/DNS server 2012 with about 30-40 users. For some reason, every couple of months (last time was 6/5/20, not today), it fills the scope with BAD_ADDRESS entries. Subsequently VPN users start calling me. I have never found a definitive answer as to why this happens. Each time I look around, can find nothing about it and just delete the entries. A few may trickle back for a bit, but essentially it just goes away. In the image below you will not the "Unique ID", which for other entries is their MAC address, is different. It always looks like this.
Anyway, any help on how I can track this down would be helpful.