Mari, at least we’re not alone! I’ve tried everything you suggested, even to adding code to the Finder library file...that worked once but soon reverted back. I don’t have Apple Care and there is an Apple store near to where I live but getting an app’t takes quite a while. There is a Mac certified repair group here that has a great reputation and is pretty reasonable. I’m going to try them tomorrow.
I’ve been working on backing up my 50,000+ photos online and just get started with another folder when the d*** Finder acts up. I would gladly go back to El Capitan OS but am afraid to try as I can’t backup to Time Machine now and am afraid of losing everything. At least my photos and scrapbooking stuff are on separate EHDs and I’m not worried about them -yet.
Thanks for your reply; I’ll keep you posted on any success or not.