Apple Watch Series 5 - Poor battery life and battery data

I've had my Apple Watch Series 5 44mm since May 21 of this year. Everything was working perfectly well until about 10-12 days ago. I started to notice that after about 12 or so hours of minimal use, the battery was practically dead, or appeared to be. Either the face was completely off and holding buttons down did nothing, or the red charging indicator was on the watch face.

What I found odd is that shortly after hooking my watch up to my Apple brand charger, my phone would display that my watch was anywhere between 11% to 43% battery depending on the day. Not sure why the watch would turn off as if it were dead if it had 43% battery left. The watch was also not notifying me of low battery and asking if I wanted to put it into power reserve mode. It would just turn off completely and would only turn on again when charged.

It was today that my battery ready 11% immediately after charging it, and I know for a fact that it was in the 50's an hour or so before that. Again, very minimal use within that hour. Only had the time showing (no complications), lowest brightness setting, no music stored on the watch (I have about 25.4GB of 26.9GB free), no 3rd party applications on the watch, only 2 watch faces added to the watch. Within 1 minute of my watch charging, it was magically up to 22% battery. This does not seem like accurate reporting of battery data.

I have taken several steps to try to fix this issue. These include:

• • Make sure software was up to date on both phone and watch (iPhone XS Max is running 13.6, and Apple Watch Series 5 is running 6.2.8 - Side note, sometimes when I search for a watch upgrade, my phone says "Unable to check for update: An error occurred while checking for a software update").
  • closed all apps and turned both devices off at the same time, and then rebooted them, starting with the phone.
  • Unpaired and re-paired the watch.
  • Removed all third party apps and all but two watch faces, "Numerals Duo" and "Activity Analog".

I waited a full day between each of the above steps to verify whether the issue was still happening after each step and after a full night of charging. The most I get out of my watch when using the the watch face with complications is about 12-13 hours. This includes 45-60 minutes of using Apple fitness app, and then literally only glancing at some text messages throughout the day. I do not send messages or emails, do not make or take phone calls on the watch, nothing. And I'm still lucky to get over 12 hours of use on the lowest brightness setting (I do have the always on display turned on).

For a couple of days I tried having only 1 watch face on the watch, without any complications. This typically got me through an entire day, ending at about the high 40s or low 50s for battery. But let's be real. Who buys an Apple Watch to use only 1 watch face with no complications, and no third party apps?

I've found others online with almost this exact same experience, so something is definitely wrong with the battery and/or the data being reported to my battery widget on my phone.

If anyone has some insight into this, it'd be greatly appreciated. Was so excited to upgrade from my series 0 to the 5, but the excitement is short lived.