[tvojaMama]

Here's the desired setup:
As far as I understand, my router can work in 2 modes (one is the desired router mode). The one I'm using now (please explain this mode), is the one I don't want, because the AP is completely unsecured. From the modem, an ethernet cable (has internet connection) goes to the router, specifically into one of the ports, which are for devices, so it's not the WAN port. In this configuration, it somehow works, but when I plug the cable into the WAN port (for router mode), it doesn't. When I access the router administration site (192.168.1.1) in the current configuration (cable not plugged in WAN port), I get to the ISP administration site for a different router:  
When the cable is plugged into the WAN port (router mode), I get to the administration site of my router. Obviously, something isn't right with my router configuration. This is my router: http://setuprouter.com/router/linksys/wr...nshots.htm What could be the problem? How do I solve it?

[tvojaMama]

Update: I managed to change the security to WPA2 and the encryption to AES. Still not in router mode. Laptop connection is normal, but phone connection is really slow or not working at all.

[mothered]

Update: I managed to change the security to WPA2 and the encryption to AES. Still not in router mode. Laptop connection is normal, but phone connection is really slow or not working at all.

On the assumption the DHCP has assigned the IP addresses within your local network and the ARP has mapped them correctly to all devices, aside from your cell phone, what happens when you connect other devices? Are the connections stable and responsive?

[tvojaMama]

Update: I managed to change the security to WPA2 and the encryption to AES. Still not in router mode. Laptop connection is normal, but phone connection is really slow or not working at all.

On the assumption the DHCP has assigned the IP addresses within your local network and the ARP has mapped them correctly to all devices, aside from your cell phone, what happens when you connect other devices? Are the connections stable and responsive?

Connections aren't really stable or responsive enough to my satisfaction. It's weird, because on laptops, the connection works great. The network mode is set to automatic DHCP and the DHCP server is enabled.

[mothered]

Connections aren't really stable or responsive enough to my satisfaction. It's weird, because on laptops, the connection works great. The network mode is set to automatic DHCP and the DHCP server is enabled.

On the devices that are not performing as expected, do an Isolation test whereby only "one" of those devices Is connected at a given point In time. See how that device performs on It's own. Disable anything that may potentially be causing a loss/lag In connectivity (firewalls, VPNs etc). On your phone, If there's an option of "search for Wi-Fi networks" (or some variant), once you've connected to your AP, disable that feature.

Given your lappies work fine, It doesn't seem to be an ISP or AP Issue. I'm just trying to establish why there's a connection loss on a device-by-device basis.