Independent Track Loop Mode Key Editor cursor out of phase

In Independent Track Loop mode on my system, the Key Editor cursor quickly gets out of phase with the cursor on the main timeline.

I can’t tell what triggers the issue, but it appears to occur if the cursor in either is scrubbed/moved with the pointer.

It operates as expected when a midi segment is looped in the Key Editor the first time, but with much navigation it quickly it plays out of phase with the main timeline.

No amount of closing and opening the key editor, turning looping off and on, adjusting the loop locators, or closing and reopening project or programme will fix this.

Local support suggests installing only basic graphics card drivers, but if that’s required I will lose the ability to switch between user profiles. I notice that there is a reported bug with respect to the cursor in the key editor under some circumstances. Maybe this is related.

Cubase 8Pro, WIndows 7, HPZ400 Workstation, Quadra 2000, 12GB Ram