[plagiat0r]

Windows 10, 11 and most major OSes have ipv6 enabled and it is preferred. There is also a Happy eyeball algorithm browsers use to connect - RFC 8305.

However, the most important thing you need to understand are fundamentals. Today we have two independent internets. One is IPv4, other is IPv6. Your server/virtual machine must be connected to both internets at the same time - we call it dual stack. Those networks are independent of each other, so make sure you're connected to both, or face the consequences of not being connected to one of them. There is not one Internet, there are two Internets nowadays.