Iphone 5 forgets my Restriction setting "Explicit content"

Hi all,

I'm facing this weird issue. I did a restore from backup yesterday and since then I cannot listen the explicit songs properly. I allowed the explicit content in Restrictions and when I set this setting it is fine for a while and after several minutes or half an hour it goes back to just the Clean songs and I have to set again the explicit ones. And this is how works, in the last hour I had to allow 3 times playing explicit content, even though I have not changed it!!!

Can someone please help me how to solve it?

Thank you.