Try disabling ”Find My” for the APMHeres hoping this brings back the great standby battery life I got with 4A400 on my AirPods Max. Prior to 4A400 and later firmware, I was/am losing around 10 percent whilst in the case, over a 18-24 hour period. With 4A400 I was only losing 0-2 percent.
I've said this since every firmware update since 4A400, so I'm not expecting this latest firmware to solve it.