Those players are probably out of your 5x points. Maybe they were goldcoins before so you could attack them, they returned so now you cant attck them, because they have 2 little points compared to you. And having 0 miloitary points or 55k, it doesnt matter. Your networth is important for 2x and 5x range, not military points.
even 0.5x or goldcoins also not able to attack now... very confusing! i tried to change other browsers, 4 types but yet still the same thing happened... is it anything caused becoming like this?