@Lynsey0574 This is getting strange now, is this one or more wireless wifi devices having an issue, are any off them working fine, your reply although not fully defined, the ! mark, you are connected but your device is NOT connected for internet access, but the NO bars is the strange one, that is you have lost all wireless wifi connection completely.... Sorry just had to jump out and read the rest off your post, if this is only the mobile devices having issues on the wireless you need to go that way and look, what type off mobiles make/model and with the sky SR203 model you have, turn it off for a couple hours, YOU may just have to factory reset it do you think that is a possibility do not like giving that advice especially if the Hub has been setup/changed in any way/shape or format, if you have not it's a fairly simple thing to do!
