Locked-in battery syndrome
In the past, when a desktop PC was turned on and the BIOS date and time defaulted to the reset date, the problem was usually a failing real-time clock battery. The repair was simple. Replace the lithium cell on the motherboard.
I have this fault on a powerful desktop PC that is fitted with a modern graphics card “module”. The module is a tight fit. The length and depth of the module are so large that they just fit within the available motherboard space. The width covers over two of the PCI-E sockets. The edge of the lithium