Well, I have applied all the options about proxy settings with the same result of long time for opening websites when first start of firefox. During these months I took notice to the one point, i.e. if I open website using firefox in the earlier morning there is no problem with the speed of opening as well as if I open another browser of edge the last one opens website without any delay. So the challenge of long time opening websites when the first start of firefox is still in force. How to resolve this?