The Application frame need many clicks before it wants to move.
I have to click about 5-10-20 times on the Application Frame of InDesign CC 2018 to make it move. I tried to click on different places and it still the same problem. Sometimes it works on the first clic, but more often i have to click many times. I'm on Mac OS 10.11.6, InDesign 13.1. I had the problem on the trial version, i called Adobe Technical service, and they told me to update when my licence will be activated... but it is now, i'm on the last version, and i still have the same problem.
Karine Breton commented
I forgot to mention that i tried to throw InDesign Preferences, restart, shut dow, and it still doesn't work.