Apple Watch battery drain after pairing with iPhone 13?

I have an Apple Watch SE. I recently (4 days ago) upgraded to an iPhone 13 from an iPhone 11. I’ve noticed that in the last 4 days, my Apple Watch’s battery drains throughout the day to the point where I leave for work at 7:15 am and my watch is dead by 2 or 3 pm. I work a desk job so activity and excessively using my watch isn’t the problem. I’ve paired and unpaired it twice to see if it was a pairing issue. I’ve optimized battery in all the ways Apple has suggested and it’s running the newest watchOS.

I did not have this issue literally 5 days ago when it was paired with my iPhone 11. This is really frustrating and I won’t be buying a new Apple Watch because I know mine is in great condition. Please help me with this issue.