This is almost certainly your ISP (or tunneling configuration), not the content providers screwing up, as networks like T-Mobile and Verizon are quickly becomin

This is almost certainly your ISP (or tunneling configuration), not the content providers screwing up, as networks like T-Mobile and Verizon are quickly becoming IPv6-first networks. A great many folks successfully pass a majority or all their traffic across IPv6 without even being aware it exists.