Hi Logos Development.
Today I was at work on my sermon prep when I clicked on this link in the ESV Study Bible Acts 11 : 3.

The resource jumped that point (though I wish every link would open in my 'Send Hyperlinks Here' panel).
At the same time my 'Text Comparison' window removed itself from the dock and went over to its usual place on the second screen. The reference was changed to Acts 11 : 3 and all response from the three buttons on the top right stopped - even to the point they did not show the usual Red,Amber,Green colours.

Hence I am about to have to restart the program in order to continue my work.
The restart seems to have solved this oddity.
Following up on the this...
It has now happened a second time. This time 'Text Comparison' undocked itself when I changed commentaries.
The coloured dots became unresponsive and when I dragged the panel onto the main monitor the colours disappeared.
Off to try another restart!