ontravel2 wrote: Slowly getting everything imported by selecting 1 individually with the function "import then delete from source". I think most are in now, including recent images, but 2 new photos I shot today are not visible. That will be vital for my workflow and is how it always worked until now.
There might be something about your Mac's Photos Library or with your user account.
First, you should try repairing the Library. Close Photos and re-launch by option-command-clicking the app icon. It can take a while for a big Library. If this doesn't work, then you need another test.
To check out the Library, try making a small test Library and see if that works better. You can create a new Library by closing Photos and then option-clicking on the Photos icon. You get this Library Chooser window:

This Library won't be your System Library.. In this case, you're creating a test Library, of course, but you can see here that I have a bunch of Libraries that I switch between. The path to the selected one is shown below the list, and they all stay in the Pictures folder. You can switch from one to the other by just going to the Pictures folder and double clicking on the one you want to use. Or you can pull up this "Library Chooser" to pick the Library you want. You'll want to go back to your System Library for normal activity, of course.
You can put some pictures in this Library to see how it reacts. Then see if plugging in your iPad works. If the Library behaves normally, then we know the problem is with the original Library. In that case, then you should test the User account.
To test your User account, you should first put your new Library where another user can get to it. You would need to temporarily move that Library out of your own user's Pictures folder up to the general "Users" folder, maybe making a new "Public" folder there. I seem to have named mine "New Folder of Pictures."

You could put some other pictures there, too, if you want to test importing. Then you can make a new user in System Settings>Users and Groups. It's kind of fun to enter a brand new fresh user account! From there, you can double click on the Photos Library that you moved, and see if plugging in the iPad works in this new account. That will tell us if there is a problem with your own User account.
What do you think?