The interstellar navy reacted first by doing the most logical thing, reinforcing the systems surrounding the mining systems taken by the enemy and reinforcing those other planets that had been able to be defended.
However, this was just a stalemate of positions, and with all the forces acting as a retaining wall, it was very difficult to gather enough forces to retake the lost territories.
Many ships also needed repairs, resupplies of materials or complete fighters. It was inevitable to move them to the space stations to do so, and the high command of the three planets also needed to meet to make decisions. That the large enemy ships had not reappeared only meant that they were already planning their second move; the navy could not afford to be only on the defensive and lose the initiative in the war.