Hi John
Thank you for your concern. Everything’s been normal the few times that l’ve run the activity monitor during the Apple support sessions. Normally, the only parallel applications I run are word (‘office’ Mac version) and mails. But mails, seldom as a parallel application, having gotten to know Mac’s issues with exchange server.
However, though 16GB, my Mac does not have a dedicated graphics card. But then, I do only drawing reviews and checks, the main drawings being done by the assisting team.
Will now try the only recourse, as offered by apple service centre, to format the Mac (by Apple) and reload Autocad ( by me).
One thing though, I am new to Mac and only 4 months into it.

Thanks.