This paper examines the effect of dynamic spin pinning at an interlayer boundary on spin wave propagation in monocrystalline manganese ferrite films magnetized along the normal to their surface. We calculate wavenumbers of exchange spin waves, decay parameters, inhomogeneous exchange parameters, and magnon effective masses. The thickness of the spin pinning layer is shown to influence the linewidth of spin wave modes. We demonstrate that, in the competition with magnetocrystalline anisotropy, a significant role is played by “surface anisotropy” in films of various chemical compositions grown by chemical vapor transport under different process conditions.