Update: I did the suggested steps to turn ON/OFF controlled folder access between reboots, but no change. I tried to do the steps to just allow TurboTax as the allowed apps but the wheel would just spin and exit the settings screen without prompting for the application.
So obviously something wrong with Defender or the app supporting Manage Settings for Controlled Folder so then I ran SFC /SCANNOW and it failed at about 72% and indicated issues with files it could not repair.
So to resolve that I then ran DISM /Online /Cleanup-Image /RestoreHealth,
Followed by another SFC /SCANNOW which was successful and indicated files were repaired.
After doing both of the steps above, I retried TurboTax and it worked in that I was able to port information from 2017 files and do a Save As to TAX2018 files. So my system now has TurboTax on the allowed apps list with Controlled Folder Access turned ON.
