Multiplayer blocked

Previously had no problem with multiplayer. Installed all updates released until 12/15.

Used alternative MAC address yesterday, went matchmaking, tells me not connected to Xbox Live.

Cleared alternative MAC address, now it tells me “Multiplayer blocked” due to parental config and/or network settings.

MAC clearing, hard reset are no use.

All other multiplayer games work fine.

Just what? Does anyone have any insight? Hello 343 Industries?