It is a somewhat common practice to disable IPv6 when you have to deal with no such traffic. However, doing so may have some unintended consequences, like when running rpcbind for NFS sharing:
Feb 20 11:27:12 server systemd[1]: rpcbind.socket failed to listen on sockets: Address family not supported by protocol
So, don’t disable IPv6 traffic. Aim to blocking it instead. Or if you must have it disabled, read here.
PS: This is not a post advocating not adopting IPv6. This is simply a workaround if the situation arises. You need to operate in an IPv6 world.
Managing organized complexity 
Or remove all /etc/hosts entry that have ::1 in them according to https://nigelb.me/2019-01-29-getting-rpcbind-to-work-without-ipv6
I have discovered while using VULTR that everyone, especially linux developers, would greatly prefer that the world remain dual stack (IPv4 and/or IPv6) or stay with IPv4 as long as possible. When the creators of Putty and MS (with “github”) needed IPv4 addresses to work (according to VULTR support), I gave up. VULTR provides IPv6 only networks for half price. There was a financial incentive to using IPv6 only, but I gave up. I do not have a full list of things that require IPv4. VULTR support has a bigger list than I do.
Stranger things have happened. I find it strange that Linux developers would be “old fashioned” enough to view the IPv4/IPv6 transition as a way to stay on IPv4.
Mike Mazarick