I doubt it has anything to do with the 44mm specifically. Perhaps these articles will help:
If your Apple Watch won't charge or it won't turn on - Apple Support
Find out what to do if your Apple Watch Series 5 or Apple Watch SE is in Power Reserve and won’t charge.
If you still need help, contact Apple Support.
FWIW, in some cases, unpairing the watch, completely erasing it, then pairing and restoring the backup will resolve the battery draining issue after an update. (Simply unpairing and pairing again may not work.)
Unpair and erase your Apple Watch - Apple Support
Also, some people have found that simply waiting a few days after an update resolves the battery draining problem.