Windows 10 ipv6 is a huge pain in the ass. Here’s how to actually use the static address you actually configured on the interface for that expressed purpose.
1) Open powershell
2) netsh interface ipv6 set interface “<interface name>” routerdiscovery=disabled store=persistent
3) netsh int ipv6 set privacy disabled
4) netsh interface ipv6 delete address interface=”Ethernet whatever” address=<autogenerated address to remove>
5) netsh interface ipv6 set int <interface number> routerdiscovery=disabled
and “netsh interface ipv6 show addresses” to make sure they haven’t come back.
(set a static address first)