iPad 2 Airplay/Mirror icon is missing after upgrading to iOS 9.3.5

I just reset my iPad 2 to factory settings and installed iOS 9.3.5. The Airplay/Mirror icon is now missing.

This iPad used to have the Airplay/Mirror ability - we used it all the time with Apple TV and with smart TVs. But when I upgraded to iOS 9.3.5, that icon went away.

I have researched the internet and this forum, and cannot find a definitive answer as to how to fix this situation.

The network connect is working perfectly, Apple TV and smart TV settings are set correctly for Airplay/Mirror - and work with all of my various iPhones (6S+, 7, and 13 Pro Max) as well as my iPad Pro 2nd generation. So I am CERTAIN the issue is NOT the network, or the Apple TV settings, or the smart TV settings. ONLY this iPad 2 with the latest 9.3.5 is missing this icon.

I have turned ON/OFF Bluetooth, I have turned ON/OFF the iPad and the TVs, I've made sure to turn on Apple TV and smart TVs before turning on iPad - nothing brings this Airplay/Mirror icon back.

I KNOW this iPad CAN use Airplay/Mirroring - I just need to know how to FIX the issue of this icon/feature missing with the iOS update.

I'm hoping someone from Apple or someone who has experienced this issue can help.

Thank you!