New HP OEM battery (PK03XL) in HP Spectre X360 is not detected by HP Support Assistant

[tactician]

Installed a new HP OEM battery (PK03XL) in my HP Spectre X360, Model: M6W85AV. It charged to 100% but HP Support Assistant doesn't recognize the battery (Battery Status: No Battery). Battery cannot be calibrated and white light next to power plug flashes continuously @ 1 second rate. BIOS sees the battery (SN 00699, 05/18/2021). Ran the [HP PC Hardware Diagnostics] Calibrate Battery manually procedure (twice) but no luck. Un-plugged & re-plugged the battery. Also removed & verified re-installation of ACPI-Compliant Control Method Battery & AC Adapter in Device Manager without improvement. Windows recognizes the battery and displays battery status. Prior to battery replacement, the old battery was detected and showed that it was weak and needed to be replaced. Computer is a HP Spectre X360 Convertible, Model: M6W85AV running Windows 10 Home Edition 64 bit. All software is up-to-date including most recent BIOS of F.54 and HP Support Assistant Version: 9.15.66.0.

Update:

Uninstalled HP Support Assistant software and re-installed the software in case it was "confused" by the original battery information. Unfortunately, that did not change the symptoms. I obtained another new HP OEM PK03XL battery and it was not detected either. Interestingly though, BIOS reported the same Serial Number and date as the the first new battery (SN 00699, 05/18/2021). Both batteries were manufactured 2021/08 according to the external labels. The new batteries appear to be functioning OK at this time but they are not detected by HP Support Assistant and the white power light next to the power jack continues to flash at a one-second rate.