If you updated your phone to one ui then you may facing problems like otg not working some apps not starting and sometimes they lags too much Slow charging fast battery drain I have a solution for this problem You have to downgrade your phone to oreo But the problem is how to downgrade android system without losing data If team samsung read this post Then please give us back our old Samsung experience ui As a software analyst i saw that one ui is not stable for many devices like j series and on series As well as some bugs in A series
you cant downgrade OS once installed without rooting the device for this issues do Hard reset once after update before take backup of your data Incase of Apps it also depends upon app dev & its algorithms battery issues will obviously rise after major updates as device compatibility is affected
