This work investigates the response to external optical feedback of a hybrid plasmonic semiconductor laser. Intensity noise measurements reveale the relaxation oscillation frequency whereas tabletop feedback experiments unveil a stronger reflection immunity, with a margin of 8 dB in comparison with a standard semiconductor laser made with a dielectric waveguide. On the top of that, the hybrid plasmonic laser does not exhibit a typical route to chaos but rather sustained induced-feedback oscillations instead. These results unlock new properties of hybrid plasmonic semiconductor lasers and provide guidelines in designing laser sources for on-chip hybrid plasmonic integrated platform.