Always were unhappy with ElvUI's buff sorting by expiraton time: constant buffs (i.e. paladin auras or mounts) always been counted as having lowest expiration time, which is wrong, obv.
So, I've added a string to the file ..InterfaceAddOnsElvUIModulesUnitFramesElementsAur as.lua
seek line 386: if not name then return end
add a line right under it: if not expiration or expiration == 0 then expiration = 999999 end
save file and then /reloadui ingame or just relog.