Please bring back the old type of practice
I enjoy all the features in Duolingo but I miss just practicing what I learned over and over again. The timed practice is nice but the old version (which is the one in the iOS / Android apps) is better, and besides variety is always welcome. Repeating lessons is not very rewarding in points, which is a great incentive mechanism. Quickly running down the tree is no good for me, I need to take it slow.
I can think of two possibilities. First is you may have some kind default page zoom up high enough the icons are being cropped out and you are just hitting enter. And that defaults to the time practice. Second Duolingo is testing a different version of the site on you. I'd post a screen shoot of the page before the practice starts.