Why doesn't my wifi hotspot security work?

[AC Question]

why does not my wifi hotspot security works?

i have updated my micromax unite 2 from kitkat to lolipop ....in which when i changed my wifi hotspot's network name & security.... but next day it always change automatically... i.e - if i choose security from open to WPA2 PSK..then next day it again change to open due to which my wifi is not secure & anyone can connect to my wifi....this problem was not in my kitkat version