The Galaxy A51 is a bit too laggy between animations and switching through apps when the device is in Medium power saving mode. This could be optimized in the next update?
how did you updated 2.1 ui ? if you simply update that big ui interface by mobile data or wifi then this types of issues arrised only...that firmware need to be flashed by odin or smart switch or through authorized Samsung service center which is one and only proper and recommended method when any big os update or new ui interface comes
then please use odin tools or wait for next update then install it by smart switch ....it's because i noticed that before also especially in Samsung devices that software or security patch creates various types of issues sometimes when software simply updateed by mobile data or wifi...thatswhy even Samsung service center also give priority of smart switch or firmware flash over mobile data or wifi
