Home assistant stops working every week at the same time

Hi.
Can anyone suggest ways that I can track down a strange problem?

Every week, overnight Sunday to Monday, home assistant stops working (cannot connect to server error).

I turn off and restart and it starts working perfectly again until next Sunday to Monday overnight.

I have checked and have no automations set up and I have turned off node red so I don’t think these can be involved

I now have no idea how to track down the problem.

Any help will be very gratefully received

Phil

Have a read of this topic:

There is some interesting information about what happens at that time (SD card checks).