Problem with connect to internet by WiFi.

Dear Sir or Madam,

today I have a difficulty, that I can't connect my three devices (with one apple_id) to the router (with internet) by WiFi.

I can connect to router (with internet) by WiFi only one device, while on the other two devices, must to be turned "off" connection by WiFi.

Tell me how to return the connection by WiFi of all devices at the one time.

Best regards,

ZzanyK.