Envy x360 won't charge (after a Windows update) even though battery & charger fine

[visaya83]

My laptop lost its ability to charge, it seems right after Windows 10 installed the KB4343909 update (OS Build 17134.228) on Aug. 14.  It could be a coincidence, but before that, everything was fine.  It did NOT happen after a power surge or outage.  It was not overheating, either. The battery was still fine, but eventually drained, as it cannot be charged whether the laptop is on or off. (The LED next to the charging port wouldn't light up when it was plugged in, either, but I know this LED works because it would blink 3 times when I pressed power once the battery drained.)

Before it eventually ran out of power, I tried all of the following (in no particular order), none of which fixed it:

• I confirmed that the charger works with another HP laptop, and I also tried the other laptop's charger. I also checked the pins inside the ends of each charger cord and they both looked fine.
• I blew canned air into the laptop's charger port. 
• I uninstalled & reinstalled the battery drivers in Device Manager, including rebooting.
• I tried to use System Restore to go back to a time before the update, but either there wasn't a restore point left when I tried it, or some error prevented the restore from even starting (I forgot which).
• I rebooted into the System Diagnostics and ran the component tests on the battery, which was fine.
• I tried updating the BIOS, but when it restarts I get the message that "the BIOS cannot be programmed because the system is not connected to external power. Please connect external power to continue."
• I tried resetting the PC, but there wasn't enough power to complete the process and it didn't take (once I got the laptop back on with a different battery, Windows reverted back to its post-update state).

I also did many  power resets by holding the power button for 30 seconds to drain any residual charge, some with the battery removed and some with the battery in. Besides this, with the battery removed, I plugged the laptop in, but it still would not turn on (which makes me question if it's even a Windows issue). I've tried these things multiple times over the past few weeks, sometimes with several hours or days in between to make sure the battery was fully drained

I bought and installed a new battery, even though  I was skeptical it would make a difference. Again, the laptop runs until the battery discharges, but it will not charge.

At this point, I've exhausted all the solutions that I've found online. The next time I turn the laptop on, with this new battery which has about 50% power, I'm going to try the resetting Windows again (hopefully it has enough power to complete the process this time?), but since the power is so precious, I figure I should ask if there are any other potential solutions that I should try before the battery is drained again? Thanks in advance.