I have same issue I updated bios like it said to and had right update and then the battery now wont charge at all and I had thought it may just be bad so I had replaced and still it is not charging the battery it shows plugged in but I have now narrowed it down to yes 100% Its The Bios Update By Razer Does 100% as a fact on the Razer Blade 14" 7700hq model RZ09-0195 make the computer not able to charge the battery. If you update the bios as they recommend on there website. On Only Some Of The Models Some Have Not Had The issue but I believe from talking to those people they sent in there computer at one point and got a new motherboard at one point before after doing research or had sent in the computer for some reason then the bios update worked but for people that had zero issues that updated the bios it makes it so it does not charge after the bios is updated so Razer Please Help This Is A Real Issue.

my Razer Blade Stealth 2019 is also almost unusable when not plugged into external power. The CPU is stuck at 0,44 Ghz and even small tasks make teh system totally unresponsive.
With external power it works like a charm

As an owner of one of these laptops, these updates did not resolve the issue for me, and furthermore I also experienced issues with the CPU performance suddenly, inexplicably dropping because of power limits.

A youtuber named Brad Ling investigated these problems and found that they are likely a part of the EC firmware, but do not seem to be resolved by this latest update. You can find the video if you google search "Razer Blade Stealth 2019: Ridiculous Power Throttling"

Incredibly disappointing. This laptop has so much potential.