15.31 Battery drain

After updating my Fenix 8 (43mm) to firmware 15.31, I’ve noticed a significant increase in battery drain. On the first night after the update, the battery went from 100% to 0%. The following night, it drained about 20%, which is roughly 3-4 times faster than before the update. Noticed a dropped in non-sleep mode as well, but its not a drastic change. why is the battery draining so much more in sleep mode? 

Has anyone else experienced this? Any ideas on how to fix or troubleshoot this issue?