Spotify on Chromecast broken, incorrect Akamai CDN resolution

For the past couple of days I've had this behaviour: I can connect to a Chromecast device from my Spotify apps (desktop & mobile), but track audio never plays, device just waits eternally for stream to start buffering.

My LAN DNS set up is this: OpenWRT router, running dnsmasq (port 53), forwarding queries to NextDNS CLI (localhost#5300), with my profile non-encrypted IPv6 & IPv4 addresses as fallback. Normally requests go through the DoH proxy and this works fine.

While trying to diagnose the issue I disabled forwarding to NextDNS CLI, so just using those direct NextDNS server fallbacks, Spotify started working again.

Problem is audio-ak-spotify-com.akamaized.net resolves to wrong addresses on DoH, at least on my endpoint https://dns.nextdns.io#67.219.103.157,103.137.14.21

CLI resolves it to: 23.62.231.48, 23.62.231.56, 2600:1415:e000:1::173e:e730, 2600:1415:e000:1::173e:e738

Unencrypted NextDNS resolves it to: 149.135.80.152, 149.135.80.203, 2600:1415:3400::1730:fa98, 2600:1415:3400::1730:faa8, 2600:1415:3400::1730:fab1, 2600:1415:3400::1730:fab2

(Unencrypted shows audio-ak-spotify-com.akamaized.net appear in my profile log, so presumably my ISP doesn't intercept/override the result, but I'm just guessing.)

Traceroute for 23.62.231.48 shows routing to overseas (from Australia), and server itself is unreachable. 149.135.80.152 looks like correct route (Melbourne -> Sydney CDN server), pings fine. Looks like a geolocation configuration issue. Which is honestly a shock, I've never noticed this on NextDNS before, does this happen more than I realised?

Re-enabled forwarding to NextDNS CLI, but with a dnsmasq override for audio-ak-spotify-com.akamaized.net to the correct IP. All works fine, (but obviously it's just a band-aid).