If you have to login in more than just one time a year this is almost always indicative of one of three problems:
1. Your router is hooked up to the wall Ethernet port of your modem incorrectly
2. Your router is misconfigured as a bridge or AP instead of as of a router
3. Your username is being used to login behind more than one device (or being shared by multiple roommates)
To make sure it is not issue #1, make sure your router is connected to the wall port using the WAN port. It will be the one port that is a different color on your router. If the cord to the wall is plugged into a switch port which there are 4 or 5 of the same color that would cause this problem. To fix this, connect the Ethernet from the wall into the port which is a single port, marked WAN and is a different color than the other ports. Then power cycle the router.
To solve the issue if it is issue #2, you will need to login to your router and make sure that it is setup to use NAT and DHCP. If it is an Apple router here are directions for that:
If you don't know how to do this, contact your router manufacturer for assistance, let them know that you need to have your router setup for DHCP and NAT.
If it issue #3 then you need to make that you are not using the same username behind multiple routers or devices in your apartment. This can occur if you have multiple Ethernet ports in your apartment and roommates or devices are logged in with the same password while plugged into different ports.