Relatively new iFixit battery no longer detected (PPT001) - any ideas?

I replaced an aging battery in my Late 2013 MBP Retina on 9/9/2021. On 1/3/2022 it is no longer detected. I have performed the usual steps (e.g. reset SMC, reseat the connectors, etc) with no change.

I’ve replaced a few batteries, this is the first time I’ve had one go ‘missing’ (PPT001). CoconutBattery and related images are attached.

I’ve tried the original AC adapter as well as a brand new backup with no luck. AC Adapter light is amber. Light does flash green once on reset. Laptop is relatively clean, never any water damage.

Performance appears to be degraded - feels like it’s running at 80%. No weird fan issues. Laptop simply shuts off when AC is unplugged.

Any help/steps to troubleshoot further are greatly appreciated.