Cubase 9.5 and Ivory II clicks and pops

Hi. Trying to use Ivory II with Cubase 9.5. Tried buffer settings and disabling external drives and ethernet, but after playing the Ivory II vet as an instrument track, I will get a click after a while. I tried different ASIO settings in the Guard section and tried varying my buffer sizes.
I am running on a MacBook Pro Sierra with a Scarlett 18i8 interface. I am using a usb keyboard for my instruments.
Is this a problem with Synthology’s Ivory II Bosendorf/Steinway, or a Cubase and audio interface problem???
I am running cubase in 32 bit 44.1kHZ.