cannot join realm,backups file issue.

hello I have a problem when I want to enter realm, a few hours ago I can still access and there are no problems when I log in. but when I want to enter realm again it always can't enter realm please try again later and I also check backups there says please check your internet connection,i try re login my account and stiil the same as before.
i check my connection but my network is good and there is no problem with my network.