Can't join a league

So I was trying to finish the league pass so I joined the leader was 100 that was level 100 and I completed and then when I try a few differently also so after like I tried like four five times I couldn't join my normally back and it keeps on saying sorry check your internet connection so how do I have to solve this because I really want to lose out on those gems that I'm supposed to be getting tomorrow and Thursday so if anyone can help please assist me as soon as possible