After the previous incident Alex decided to stay inside the Earth for a few days and at the time even though spiritual energy of the earth increased but no powerful portals appeared on earth. So you can say that the situation once again became normal and those fighters could focus on increasing their strength at the time.
In that previous matter even though most of the fighters were able to defeat those Monsters and were able to clear the photos, that does not mean they didn't need to increase their strength. At that time many fighters got seriously injured and also many of them got injured. Other fighters even though did not get seriously injured but still it shows them that they were still weak compared to those Monsters.
