Power Saver Mode Not Working on Paperwhite 12

I have a PaperWhite Generation 12 Signature Edition acquired brand new March 20th of this year. It is on firmware 5.18.4 - the latest. It has been working nicely with a battery life of about 6-8 weeks. However after a charge on Friday, I noticed a higher than normal battery drain. Down to 84% this morning, Monday - 3 days later. One thing I noticed is that although I have Power Saver / Low Power mode enabled, the device is not honoring this setting anymore. Meaning that as soon as I open the case, the device is on without the “waking up” message. Also I have sleep setting set to 5 minutes.

I have tried flipping the power saver mode on/off again as well as a reboot while plugged in which is something suggested in other threads. Also I confirmed that no books are indexing at the moment. Any ideas on a solution here? I could do a factory reset as a last resort.