Unable to turn on my Apple watch 6 after updating to watchOS 11.4

Was fine until I performed the latest update today (Watch OS 11.4) then ran out of battery about 3 times as fast as usual, put on the charger and when I came back after an hour, the screen was black, unresponsive and won't respond to either button, together or alone. Checked 2 different chargers, including a brand new one, no response. The back of the watch is warm, but not hot.

After 30 minutes on the charger, still no lightning bolt. This a "new" Watch 6 (replaced my and my wife's watch 6's last fall, after failing batteries. For $100 each, Apple basically replaced the watches with new ones of the same model.) No sign of battery failure on the renewed watches, no difficulty until today and the update.

[Re-Titled by Moderator]