MB 5x when selected a tab and get inactive, blue rectangle shows up

[unknownguy]

When having MB5x opened and you have selected a tab.

Then run as example calc and it gets it as active window. When going inside MB 5x again you will notice a blue rectangle around the tab.

I have run into these many times before but never understand how I replicated it. Example image below.

[brad03]

yup also got this once myself but have since not been able to replicate. 

[unknownguy]

1 minute ago, brad03 said:

yup also got this once myself but have since not been able to replicate. 

Some times it works. Some times not. I have tried the steps I wrote but didn't get it some times.

[icolcear]

That is the focus rectangle used for keyboard accessibility. Maybe you pressed tab by accident?