  We have investigated transport through graphene Andreev interferometers
exhibiting reentrance of the superconducting proximity effect. We observed a
crossover in the Andreev conductance oscillations as a function of gate voltage
($V_{BG}$). At high $V_{BG}$ the energy-dependent oscillation amplitude
exhibits a scaling predicted for non-interacting electrons, which breaks down
at low $V_{BG}$. The phenomenon is a manifestation of electron-electron
interactions, whose main effect is to shorten the single-particle phase
coherence time $\tau_\phi$. These results indicate that graphene provides a
useful experimental platform to investigate the competition between
superconducting proximity effect and interactions.
