cubase 11 freeze fabfilter q3

just upgraded to cubase 11
on high Sierra , iMac 27 2015 with 2 extra monitors

if I open more than one instance of Q3 on a track cubase just hangs, had the same issue with 10.5 but just simply didn’t use it

any ideas? I unplugged my other monitors incase it was that

works fine in cubase 10 no issues ,

thanks in advance

Cubase is only supported on macOS 10.14 or newer.

I have friends on high Sierra using 11 with no issues ? I really don’t want to risk upgrading to find something does work
any one else upgraded to 10:14 and solved this issue?

going to upgrade to 10.14 see what happens hope this solves it