I an having a similar issue although i believe this has happened to my computer because of zoom while it hasnt shut down on me before during use.
When i first downloaded the update it happened the next day but i was able to do the power off and up volume button to work after multiple attempts of button combinations.
Then i uninstalled and reinstalled zoom about a week later and the day after my last meeting (today) it has now done this again except it continues to turn off by itself multiple times and i have encountered many different screens when successfully able to find the right combination of buttons after a million tries.
not sure if it is hardware or what bc the shutdown has prompted by itself, when i use the mouse to click, or when i have moved the tablet and it wont turn back on although charging fine.
during the times i was able to get it on working for a few minutes with hope, i updated the most recent update but then also did the diagnostic test above and it recommended the bitlocker update which i have to have done by a support person apparently.
ugh not sure how often this shut down has occurred for you