When I click the tick in the bottom left hand corner of the training image the image just shrinks briefly and the tick doesn't turn blue. To be able to get the tick to turn blue which means it is selected, I need to hold down the left mouse key when I click on the tick and then move the cursor back over the tick until it turns light gray. This makes selecting multiple images very time consuming and fiddly. I've tested on Chrome, Firefox and Edge and all 3 browsers have the same problem.