Windows Airplane Mode laptop charging
If Windows is set to Airplane Mode, this can prevent your battery from charging while in Airplane Mode, even after reboot or booting into Linux. The change is persistent even when booting into Linux–perhaps a no-battery-charge flag is set in the UEFI BIOS.
Windows in Airplane Mode prevents battery charging.
Laptop charge after Airplane Mode: go back into Windows and turn off Airplane Mode to allow charging the battery.
Re-enable battery charging on Windows and Linux--observe Airplane Mode is not highlighted.
The reason Lenovo gives for disabling battery charging in Airplane Mode is to avoid tripping the airplane seat power outlet circuit breaker. Seems fair, but they should have a popup message reminding you of this fact.