@Natas66 which generation of chromecast are you using, got a link? can you see the m7450 wifi on your chromecast showing your wifi settings while connecting to the wifi may help

@DamnNATtype have you try set your ps4 ip as DMZ host?

@a7medhameed Have you try clearing the caches in your browser or try another browser?

@DOSSIP47 Is the m7350 that disconnect all you devices or the devices disconnected automatically because of "connected but no internet" maybe you can ask the technical support for a latest beta...

@tkerby please have a detailed description about all the operations you have done to the deivce since you got it, and if possible, show the logs of the recovery tools you have tried. there are a few...

@Franz99 May I ask your location(country), pls？