Why do some services not work correctly in Firefox?

Question

Google

For some reason, some services do not work correctly in Firefox, but at the same time everything works stably in Google Chrome.
For example, automatic scrolling of the list of tasks does not work in Wunderlist when moving a task item (that is, when the list of tasks is large, and we need to move the last task to the top of the list, hold down the RMB, drag the task to the top edge of the list and the list itself scrolls up, but in Firefox this the function doesn’t work for some reason.)
There are also problems in the Google Keep “notebook”, if you open one note, work with it, then close it and when you open another note, you can’t add anything to it, it is treated by updating the page, and in older versions Firefox Google Keep works flawlessly.
On YouTube, such a picture is occasionally observed, when the next video is played, the video starts, while the page has not yet fully loaded, the video plays for 10-15 seconds, then the page finally immerses and the video starts playing again. It used to be okay with this as well.
Characteristics: OS Windows 7 SP 1
Firefox v.41.0.2
I tried to restart the browser without add-ons (that is, in safe mode).

Answer 1

Krivoruk developed
+
focus on the majority
alexvaleev.ru/browserstat/2015/9/1