New iMac runs slowly after a day or so
I bought a new iMac a couple of months ago. When it starts, everything is fine, but after using it for a day or so, it starts to go really slow, taking ages to save or open simple files and applications.
A restart fixes it, but it happens again after a day or so.
I've tried disk repair, etc., but can't fathom what's wrong, or what's causing it.
Any advice?
iMac 27″, macOS 10.15