Thanks for reaching out and sorry to hear that you're having a connectivity issue with your Chromecast. Let's sort this out.
A few questions: What type of Chromecast device do you have? What's the LED light status in your Chromecast? What mobile phone are you using to connect your Chromecast? Are you getting any messages when connecting it to the 2.4 GHz network? Were there any recent changes in the network?
Try these steps:
Let me know how it goes.
Glade to your reply.
i have the latest chrome cast, i don't know whats called but its white device with white controller, any way
the led color is white as usual
some times when its trying to connect to 2.4 hz its giving me authentication problem whit out getting internet in it, tried to change the password of the wifi with no result
and sometimes its connecting to 2.4 but not usually but when it comes to 5.0 hz it connecting normally
Thanks for the swift reply. Have you tried the suggested steps above? If yes, how was it? Also, if you're familiar with your router settings, please check the settings for the 2.4GHz band. You may also reach out to your Internet service provider to check this for you.