unable ton load new software

I am running a mac mini pro2020 running Sequoia  os 15.1

I have an iPad 8th generation and an iPhone XR

I tried to update the iPad and iPhone by connecting them to my Mac Mini as I have done

for a few years but I got an error message that I needed to repair and then reinstall the software.

I clicked Ok and the process stopped and the Mac no longer showed the iPad as active.   

The iPad showed that I needed to connect the unit to the Mac mini and the same procedure needed to be run and failed again.

Has the upgrade process changed with the release of Sequoia?