It's not really a bug, but this last major update has made some subtle changes to accessibility mode which impair the functionality of the UI for those who use it.
The first change I've noticed is the most annoying, and that is that you cannot hover over skills in your bar to see a preview of them like you previously could. This has meant that when I'm levelling skills, I cannot just hover to see their progress and need to completely open the skill menu, navigate to the skill, and check its progress that way (making it impossible to do quickly like before).
The second change I've noticed that has been annoying is less of a detriment, but it has to do with champion points. The ability to select branches of the CP tree (green red or blue) has had added functionality to use mouse in accessibility mode (like the quickslot wheel which is great!) except that when using arrow keys like previously, it has reversed the arrow used (it used to be left = green; up = blue; right = red). Now it is left = green; DOWN = blue; right = red. This one is more minor and less of an issue, but is also annoying to have to relearn controles after years of playing in a particular setting