Same here. MBP 13" Retina (Early 2015). 250 battery cycles and working perfectly fine prior to the Big Sur update which bricked the battery. Now shows 'X' through battery icon with a 'Service Recommended' warning. The battery health is now at 0%, maximum capacity of 0mAh, and will not charge. Indicator light on the magsafe plug remains green and as soon as power supply is unplugged the MBP immediately turns off. I spoke to several Apple advisors who knew about the issue, and they booked me into a Genius Bar. I took my MBP in today and although they knew of the issue, they said my 2015 MBP isn't part of the 2016/2017 eligible models which Apple fix for free due to this issue (https://support.apple.com/en-ca/HT212163). The release details for Big Sur 11.2.1 state 'addresses an issue that may prevent the battery from charging in some 2016 and 2017 MacBook Pro models.' so this is a known issue by Apple, but conveniently older models like my MBP 13" 2015 are not eligible for Apple's free battery repair to resolve this issue. My MBP and its battery were inspected by Apple and found to be in very good condition with no signs of damage. And since the battery issue happened directly after the update I do not believe this is a hardware issue. I believe this is a firmware issue as part of their recent software update. While the 11.2.1 version addresses the issue for MBP's yet to have had the recent update, it does not rectify MBP's which were updated and are experiencing this battery issue and firmware cannot be downgraded, so reverting to an older OS doesn't fix the problem as others have said. The proposed solution by Apple was that I the customer should pay $259+tax CAD for an Out of Warranty battery repair. I declined and said that Apple is obligated to include 2015 MBP's as part of eligible models in the battery replacement scheme. I am still waiting to hear back on their response but will keep you all posted.

Update to above: Apple are not taking liability for their software update which turned a perfectly healthy and fully functioning 2015 MBP into a ‘desktop’ which now needs to be permanently plugged in due to the battery bricked and not charging past 1%. However they are repairing the same issue with all the same symptoms for 2016/2017 models. To add insult to injury they recommend I not only pay $259 for battery replacement but I also pay $500+ for a new logic board since it didn’t ‘respond’ to their diagnostics. Hardware recommendations for software/firmware bugs? I declined Sorry Apple but you have lost a once loyal customer as this is no way to get consumers to upgrade from older devices. Devices which were working perfectly prior to an update.