I have had this problem right from Leap 42.1 through to now Leap 15.0. Firefox takes a long time about two minutes to load. I had put up the problem in Install, Boot, Login forum but have not found any solution. However, there was a suggestion that FF was searching for some site or url which was causing the delay. So I turned the internet connection off and then tried to load FF. It came on instantly!
I work mainly in KDE but the same problem exists in Gnome too. I use Network Manager not Wicked. I set the application to open to a blank page. On licking the FF icon the indication that it is loading comes on in the panel which disappears about when one expects the application to come on. The application comes on after nearly 2 minutes. If the icon is clicked again after about 10 seconds a message comes on that FF is already running.
The situation is that to start FF, I first have to disconnect the internet via Network Manager, start FF which comes on in a few seconds and the reconnect. It is not very very inconvenient but something is certainly wrong and needs to be pinned down and corrected.
That is correct. I am really sorry I did not try it out then! However I sort of remember being put off by the message saying YAST does not handle Network Manager. That additional hint to ignore warning regarding Network Manager put me on the way. But thanks a lot for your help.