Mozilla suddenly start to misbehave, like any new page which wasn’t in DNS cache or whatever fails to load, but konqueror wokrs just fine
Is that all information you have? Not even which version of openSUSE?
I’ve 13.1 and actually this problem simply disappeared, bit weird who knows some vicious goblins 
You probably had temporary DNS problems – perhaps a network problem originating at your ISP. And when that cleared up, your problem went away.