Non-standard closedowns and startups.

The closest thing where I live was when Canal 1 (RTP 1) in the late stages of the IVC era (1990 to 1992) saw the computer that generated the texts for the menus and the clocks (the one in the test card and the big old analog clock before startup and the news) failed at least two times.
https://www.youtube.com/watch?v=eqcyOQzHPt0

Radio Television of Portugal also had a non-standard closedown where they showed footage of beach scenery before moving to some shapes forming the flag of Portugal then shapeshifting into a sunset and into a night before closing its imaginary doors and forming some barely visible text.

BBC 1 closed in 1992 with the Queen (during Christmas) because some dudes at the UK BBC studios thought it was "too jolly" to use.

hey man that 1986 to 1990 RTP 1 closedown was "standard" actually.

Non-standard in the stricter sense would be the closedown from the 1980 presidential elections, becuase it ended close to 4am and they were doing overtime
https://www.youtube.com/watch?v=K3FUOsY65SQ