XPS 15 7590, Windows 10 2004, battery drain issues

Hi everyone, looking for some help/advice about my XPS 15 7590, which I have had for just over a year. The purchased 1 year warranty expired on July 12, 2020. Here is a summary of the battery issues I've been having which I believe only started after updating to Windows 10 2004:

• When the battery level reaches about 50%, it suddenly drains rapidly.
• If I put the laptop into hibernation mode at, for example, 40%, when I turn it on again the battery is at 1%. Then, when I plug in the AC adapter, it jumps to about 40-50%.

What I've tried already:

• A battery calibration (following the guide here)
• Ensured all available updates are installed via SupportAssist

Other info:

• Laptop specs: i7-9750H, 8GB RAM, 512GB SSD, GTX 1650, FHD
• I ran a battery report and wear is reported at 89.2%

I've always been careful to take good care of my battery (i.e. not letting it drop below 20%, doing a full discharge cycle once a month) and have had no issues until recently so this is really frustrating. I've been thinking I need to rollback the version 2004 update or replace my battery, but would greatly appreciate any advice or tips! Please let me know also if you need any more info.