In order to fix this, you first need to restore your printers to default. To do that, you can try going to Setup Menu > Network Menu > Restore Network Defaults > Yes. After you did this on both of them, you can try to install the printers on the wireless network following the steps provided on the support website. This should fix your problem. Use the guide that is made for your OS. Also, you can check the following forum 1 and forum 2 where this problem has been discussed.