Helllo yesterday my samsung galaxy j5 6 updated , at first all seemed fine but i had some problems regarding this upgrade . Some apps that i need running in the background no longer run as soon as i hit home and also magicly 3gb of space has been reserved . I went to sammobile and searched firmware by the model . Is it safe installing the previous formware that worked for me? and also does it really matter flashing a firmware for another country as long as the model is the same? And does this voids my warranty (im flashing a stock rom)