I have been attempting to troubleshoot some slow downloads from Xbox Live (these seem to come from assets1.xboxlive.com). In doing some digs, it appears that the Quic DNS servers sometimes change their mind about what the best source of files is, and this can drastically affect download speed. I found a link for a game to test on my server rather than trying to reproduce on my Xbox - apologies for all of the screenshots with tiny text. These results seem to correlate with what I'm seeing on the Xbox proper as well when I check which IP is being given by the DNS.

Here you can see a different response from each DNS.

Poor download speed from the Fastly server.

Ubuntu download from 2degrees is pretty speedy right afterwards as a control.

Sometimes the DNS servers agree with one-another.

Akamai served download is pretty good.

Different responses from the DNS servers again.

And poor download speeds from this one.

My question here is whether this is normal DNS behaviour. Do I just need to get lucky about which server IP I get or am I fundamentally doing something wrong here?