I'm no longer able to pair my MAC with my Iphone, why

You were never able to pair your Mac with your iPhone; iPhones do not support computer to computer communications (and your iPhone is a computer, remember) except for using the phone as a cellular modem. You also don’t need to pair it, because continuity functions, screen sharing and Airdrop do not need to be paired.

My problem is similar. I have a Late 2014 iMac Retina 5K, and a iPad mini 4 and a new iPhone SE 5. he iMac is running Big Sur, and the iPad and iPhone are running 15.4. Last week, I had a update from 11.6.4 to 11.6.5 on my iMac. Now, I no longer see my iPhone or my iPad in my Finder. I can no longer SYNCH the two with my Computer.

Any ideas as to why that is? (P.S. It worked before. )

PPS. All 3 are on the same wireless network with the correct passwords and permissions.

Been there. Done that. No Joy.

I should have said that earlier. I did try to direct USB connect both the iPhone And the iPad (Sequentially after opening and closing the finder AND after rebooting the iMac.

By the way, all 3 devices are wirelessly communicating with the router that is sitting on the desk 2 feet from them

Sync each using a cable. Sometimes Wi-Fi sync doesn’t work after an update. After you sync once with the cable Wi-Fi will probably work again.