Can you please Private Message(PM) me your Username/CID/Service address for the service you need help on so i can pull up your account.
Sorry for the late reply.
I have checked your NBN-FTTN 12/1 service on our NBN test portals and all tests are passing.
Speed is also good at 11.40mbps.
If it drops at exactly 12am every night, do you have an unused alarm system at your premises? It almost sounds like an alarm system to programed line checks at the same time each night.
Something to consider.