GUI scale error on 3.5"

I can't change the GUI scale on my Allview A4 You 3.5" phone (actually I can but it remains the same)....This bug is from the first 0.15.0 beta but in 0.15.X i can change it only to the max and the min and not what i need...Because I thinked it was from my phone I teseted it on my body's Alcatel One Touch Pixi 3 3.5" and the Same and I tested it on my mother 4" phone (that's ironic no =]]) and it worked normal....Please Help!