MAC projector with Robin BCs needs initialization every time. The

underlying solver, (EB)MLABecLaplacian, is not save for reuse with
Robin BCs.

Projections/hydro_MacProjector.cpp

@@ -212,6 +212,7 @@ MacProjector::setLevelBC (int amrlev, const MultiFab* levelbcdata, const MultiFa
                                      "setDomainBC must be called before setLevelBC");
     m_linop->setLevelBC(amrlev, levelbcdata, robin_a, robin_b, robin_f);
     m_needs_level_bcs[amrlev] = false;
+    m_needs_init = true; // Solver is not safe for reuse with Robin BC
 }