Jacob Hofer

It seems that in recent versions (1.21.131), at least on switch, the data being sent for player 2 now uses both the name and XUID of player 1.

The data being sent for player 2 is:

{
  nbf=1766084826, 
  extraData={
    identity=redacted, 
    displayName=redacted, 
    XUID=redacted, 
    titleId=redacted,
    sandboxId=RETAIL}, 
  randomNonce=-835051032898776294, 
  iss=Mojang, 
  exp=1766171286, 
  iat=1766084886, 
  identityPublicKey=redacted
}

which matches the xname and xid of the data sent for player 1 (shown below):

{
  sub=redacted, 
  ipt=PlayFab, 
  iat=1766084841, 
  mid=redacted, 
  tid=redacted, 
  pfcd=redacted, 
  cpk=redacted, 
  xid=redacted, 
  xname=redacted, 
  exp=1766099241, 
  iss=https://authorization.franchise.minecraft-services.net/, 
  aud=api://auth-minecraft-services/multiplayer
}

All of the redacted data does have values, but the notable portions are xname, xid, displayName, and XUID. The formats of data sent between player 1 and player 2 are also quite different.

Turns out the bug was due to some corrupt file.