Android Private DNS (DoT) connects to far server

@olivier

I use NextDNS with native Android Private DNS (DoT), no app. If I run the ping test at https://ping.nextdns.io/ I get this:

vultr-sjc       14 ms  (anycast1)
  do-sfo          14 ms
  vultr-lax       18 ms  (ultralow2)
  zepto-lax       21 ms
  anexia-lax      23 ms  (ultralow1)
  one-pdx         28 ms
  bronto-slc      30 ms
  smarthost-las   30 ms
  frantech-las    31 ms
  tier-pdx        57 ms
  anexia-zrh     157 ms  (anycast2)

But if I go from my phone to https://dnsleaktest.com it shows that it actually uses Anexia servers in Zurich which is ... far from California.

What's going on here?