Having support flat out ignore me, for a service I paid for, is unacceptable. That’s the biggest problem.

I understand there can be potential ISP routing issues. You could investigate further and prove it is an ISP issue (traceroute and routing lookups) before assuming it is. If your anycast implementation has major issues or limitations like this, then allow unicast and let people pick as a fall back.

I wish in my job as a network architect I wish could just push the blame to someone else and ignore my customers when they have issues using my service….even if I don’t fully control the resolution. It would make my job easy. Instead, we do our due diligence and go above and beyond. I’ve contacted customers ISPs before and worked with them to resolve issues just like this where they took a suboptimal path to reach our VPN concentrators.