[battlestar]

It is normal that I can't get higher + than +3 ... Because it's failed after +3
Sorry for my english

[shadows]

Sometimes it just fails after +3 and sometimes you are lucky to get +5 without any fails.
Its just a matter of luck. But I would advice you to do daily quests so you can get the lucky buff and even invest in a premium plus, buy a avatar and add lucky to it. By having these things it should gives you better luck to plus your gear and items.
And again, its a matter of luck