@softraid-support As a stopgap measure I will create an external SSD boot drive. Once I have done that I can Certify the Apple fusion drive as you sug...

@softraid-support, thanks for the info!

Thank you! that is very good information. Since it will cost me around $400+ from OWC to replace the fusion drive, and I hope to replace this 2017 iMa...

I am happy to report the latest Apple 11.3.1 update has fixed the issue on its own. 😎