Thanks for replying.
As I figured out that the user is able to vote again and again from mobile devices but not able to do using the computer if the limitation is set to the Ip address.
And don’t know why this bug is coming, again and again, that for some entries it shows, ‘You have already voted’ whether you are coming there for the very first time and didn.t vote anyone so far. sending you the screenshot on your contact page.