My laptop has two screens and two people are successfully sharing - only annotate on one screen

[RJ50]

My laptop has two screens and two people are successfully sharing with me but I can only annotate on one screen.

Two screen annotation has been working for 5 years and suddenly stopped working - any ideas?

A second device allows second sharer annotation but I used to be able to do it from one device.

[RJ50]

Here's a link to a screenshot of the issue: https://drive.google.com/file/d/1FKFv8u9yIKDL6ucMX6EtbiBP8F0HxvmZ/view?usp=drivesdk 

[RJ50]

Screenshot: 

https://drive.google.com/file/d/1FKFv8u9yIKDL6ucMX6EtbiBP8F0HxvmZ/view?usp=drivesdk