The problem arises because the visibility of this button dependent on the active extension in Chrome.
It is either exitkiosk or virtual keyboard.
Steps to check:
1)Active extentions
Go to chrome -> settings -> extentions -> Manage Extentions
And check if these extensions are active and have no errors:
2) Don't let Google to run in the background
During one of the updates, Chrome added a change that it does not turn off but works in the background, so it is also worth checking if it is not active:
3*) RobotConfig update
If above steps helped this point is not neccessary.
If all steps are ok and this issue is still bothering the machine please update Robot Config to version 1.15.0
In this version, Ruth apparently removed the button disappearance
