Thanks for the info Kendra!
My Mac is a MacBook Pro with 16 GB of RAM and a 500 GB Solid-state hard drive and a 2.9 GHz I7 Processor. So hardware is fine. The OS is Catalina 10.15.13 which is beyond what Intuit lists on the link. That may be the problem. When using the app (up until Intuit got rid of it a couple weeks ago) I found I had to Reset App Data every time I would walk away from the computer for 5 minutes and would clear the cache a lot.
But after having to replace the app I am stuck. I cannot use the old app that worked. The new app requires disabling Mac OS Security to install, and then essentially disabled the computer by wiping out my keychain and permissions. Talking to Apple, they say the reason is Intuit did not build the app to its Catalina standards. Despite now 5 attempts, I have not gotten any answer or help out of Intuit.
So I have had to use QB Online thru my Safari browser, no app, and it is unworkably slow.