Minecraft crashes randomly while playing remotely one someone else's world.  After this, attempts to rejoin the world fail with either "unable to join world" or minecraft crashing with high memory usage.  This is specific for the gamertag/microsoft account, and occurs when attempting to join from other devices with the same gamertag/microsoft account.  It also occurs when attempting to join from an Android device, though it will just show a blue pale screen.  It is also world-specific, as it doesn't occur with different worlds.

Opening the world in rbedrock (R library for world analysis), the remote_player key contains a the value "Rotation" which has NaN for the first value, and -90 for second value.

If these are both set to '0', the player can rejoin the world without problems.

I've attached the values from rbedrock that seem to be the cause of the crash - you can see one player has NaN for the first value of Rotation, but not the other.  This is associated with the player who is unable to join.