Hi friend.
The Mobile WiFi has an AP isolation function. When this function is enabled, wireless devices connected to the Mobile WiFi at the same time will not be able to access each other. When this function is disabled, wireless devices connected to the Mobile WiFi at the same time will be able to access each other.
Log in to the web-based management page, choose Advanced > Wi-Fi > Wi-Fi Security Settings > Options and check whether the AP isolation function has been enabled. Only after disabling this function can you access other wireless devices like normal.

Thanks.