Attempt workaround to avoid missing proxy creation

src/engine.c

@@ -3190,7 +3190,7 @@ void engine_makeproxies(struct engine *e) {
 
   /* Gravity needs to take the opening angle into account */
   if (with_gravity) {
-    const double distance = 2. * r_max * theta_crit_inv;
+    const double distance = 4. * r_max * theta_crit_inv;
     delta_cells = (int)(distance / cells[0].dmin) + 1;
   }
 

src/engine_maketasks.c

@@ -1336,7 +1336,7 @@ void engine_make_self_gravity_tasks_mapper(void *map_data, int num_elements,
   const double max_distance2 = max_distance * max_distance;
 
   /* Compute how many cells away we need to walk */
-  const double distance = 2.5 * cells[0].width[0] / theta_crit;
+  const double distance = 5. * cells[0].width[0] / theta_crit;
   int delta = (int)(distance / cells[0].width[0]) + 1;
   int delta_m = delta;
   int delta_p = delta;