Spectre x360 F.26 BIOS disables charging via Thunderbolt 3

[desiato]

The HP Support Assistant suggested I apply the F.26 BIOS update a couple of days ago, so I did. Since then, I've found that my laptop will no longer charge from my external Thunderbolt 3 dock like it used to. Even worse, even if I have both the "official" USB-C charger that was supplied with the laptop attached AND my Thunderbolt 3 dock, it still won't charge!! Windows reports "PC isn't charging -- Use the recommended charger and cable, and make sure it's directly plugged in."

As stated above, even if I have the "recommended charger and cable directly plugged in", if I also attach my TB3 dock, then the machine no longer charges!

I tried downgrading to a previous BIOS version where all this used to work, but it won't let me. This is completely unacceptable -- there's no reason I shouldn't be able to maintain the features and performance I had previously. This update to F.26 BIOS has rendered my external Thunderbolt 3 dock useless, since I can only use it as long as the laptop battery lasts! This will unnecessarily increase the number of charge cycles on my battery.

Please provide a way to roll back the BIOS version so I can avoid this obvious bug until it is fixed!

[desiato]

A further note -- when in the configuration of having both the "regular" power supply attached as well as my external TB3 dock, the laptop fans are running full tilt and the remaining battery power drains incredibly fast. It's as if it runs at full speed/power off of battery.

[desiato]

I have mirrored this post in the Hardware board.