I have updgraded to Catalina 10.15.3 and have the latest updates for lightroom. I still can not tether to my Canon 5D Mark 4 or my Canon 6D. I've tried it on my laptop and my desktop. I am reading that this should have been fixed with 10.15.3 but it is not on either of my devices using either camera. I've deleted and reset my preferences files. Any suggestions?