Could be an add-on that is causing a conflict.
Try booting into "safe mode" -"disable" all of your add-ons - reboot and see if the problem is resolved. If so you will then have to "re-enable" your add-ons "one at a time" to find the culprit.
This thread is now locked and can not be replied to.
What is Amazon Go and will it come to the UK? The store without checkouts or queues
1995-2015: How technology has changed the world in 20 years
Hands-on with the Star Wars fighting drones you can fly yourself
iPhone 9 and beyond: 32 amazing future smartphone developments - graphene, supercapacitor…