In a multi-fold universe, gravity emerges from entanglement through the multi-fold mechanisms. As a result, gravity-like effects appear in between entangled particles that they be real or virtual. Long range, massless gravity results from entanglement of massless virtual particles. Entanglement of massive virtual particles leads to massive gravity contributions at very smalls scales. Multi-folds mechanisms also result into a spacetime that is discrete, with a random walk fractal structure and non-commutative geometry that is Lorentz invariant and where spacetime nodes and particles can be modeled with microscopic black holes. All these recover General relativity at large scales and semi-classical model remain valid till smaller scale than usually expected. Gravity can therefore be added to the Standard Model. This can contribute to resolving several open issues with the Standard Model. The strong CP violation problem is one of these issues: QCD predicts CP violation, yet no CP violation has ever been observed involving the strong interaction (when it occurs, it is for the weak interaction). In this paper we show that when adding gravity to the Standard Model, in a multi-fold universe, gravity allows the mass of the up quark to be smaller (close to, or equal to zero). This symmetry, or quasi symmetry, is a way to eliminate the CP violation contributions in QCD, therefore resolving the problem. It argues for evolving the Standard Model to add gravity, if non negligible at very small scales. No New Physics are introduced as new particles, which could also explain why axions have never been observed, and we may have to remove them as candidates to explain dark matter.