Sorry for not getting back to you sooner. The options would be.
1) Shorter reservoir or keeping it less full.
2) Rerouting the top off hose higher, either clamped higher on the sump or up to the tank or overflow box (sensors will remain in the sump).
3) Installing an air gap, basically securing the hose to a gutter that drains into the sump, it needs to be open at the top so air can stop the siphon. Basically bracket a 1/2" PVC gutter and secure the hose to the top of it and the water pumps into the gutter which drains into the sump.