Option key duplicate feature seems intermittent

Hi There!, I use the drag/tap option to copy feature all the time. It seems to be intermittent. In Rhino5 it was instant everytime. In Rhino 7(M1 Mac) I have to drag and wait a second before tapping the option key or it wont work at all. Around 20% of the time it takes repeated attempts before it works. My keyboard is working fine. I am using a New Mac Mini M1.
Any ideas?
Many thanks
Simon :^)