Tablet is shutting down suddenly and resetting to 12/31/1999 date

The battery is fully charged 100%. When using the tablet for a few minutes, it starts to shut down and can’t turn on. The tablet only turns on after I plug in the charging power cord, but the tablet is resetting the date to 12/31/1999 and it still shows the tablet is 100% charged.

If I continue plugging in the charging power cord while using it, the tablet functions normally for hours. Is it the battery issue or motherboard? Thanks.