Airplane mode quit working after Apple update

What exactly is it not doing?

Pretty much all airplane mode does anymore is turn off the mobile network.

Unlike the "early days" of mobile phones ... WiFi and Bluetooth can operate while in Airplane Mode today.

Also ... have you performed a full power-off / restart cycle of your device since updating?

For your voice calls and SMS (Texts), it sounds like you might have WiFi calling enabled (where your carrier routes your inbound calls via your WiFi)

See more info - including how to deactivate it - here:

Make a call with Wi-Fi Calling - Apple Support

And unfortunately ... as long as there is a communications "pipe" ... spam and robo-calls will continue to roll-in.

You’re certainly welcome.

Glad the “mystery” was solved.

Sometimes we DO desire to go “off net” 😉