Within the last couple of C11 updates the L & R loop markers occasionally become unresponsive - as in you can’t click on them and move them with the mouse, nor use option / command click to place them at the relevant point in the timeline.
I see this most often either during or after using the export audio window.
It takes a bunch of random clicking around the screen for a few seconds before they suddenly start working again.
Martin isn’t suggesting you start generally using Cubase in Safe Start Mode. He wants to see if your problem is caused by corrupted Preferences and starting in Safe Start Mode is how you determine that.
I am more than well aware of why he has asked this.
However in this case it is utterly impractical to run in safe start mode - I cannot play around in Cubase for a few hours in order to determine that a random issue that’s just annoying has been fixed due to a corrupt preferences issue. I simply don’t have the time.