Windows firewall doesn't detect SSL VPN as domain network

you might need to add the vpn segment into ad subnet:
https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/plan/creating-a-site-design#creating-a-subnet-object-design

---editors note: 3 previous sorta duplicative comments were caught in spam...copyingf forward all the unique links into this one post. Thanks zamroni777
https://www.techcrafters.com/portal/en/kb/articles/setup-ad-sites-and-subnets#Configuring_Subnet_Pro...
https://vizrt.my.site.com/NewTekSupport/s/article/Changing-your-Network-Location-Type-using-Group-Po....