couldnt communicate with a helper application

I have a MacBook Pro 2020 (i5, 13" 4-USBc) and have just installed Big Sur and I think I had the problem before Big Sur but anyway when I connect my iPhone via lightning-USBc (6s plus) IOS 14.2 or iPad Air 3rd gen IOS 14.2 I get the error "Couldn't connect with a helper application." This is after resetting location and privacy and clicking on TRUST etc. If I knew which helper app it was maybe I could fix it... The same thing is true in Music. I was under the impression iPhones would connect via the finder now.