Warning sign about cables on LG monitor

This is an issue with the 32" LG 4K monitor that has been mentioned before. But because no one replied for a long time, it was not possible to reply to the original.

You get a square message that floats above the desktop on each and every start up for approx 60 seconds. The mouse pointer will go under but NOT onto message to close. Message is (caution ) Make sure to use supplied input cables.

It has two options in square:

1. Do not display this message again

2. Close. Since You can not move to surface the choices are not available.

However, can't select either option as mouse pointer goes under the message box. (see below for my answer!)