my wifi does not reach outside but my neigbour's does. When I use my phone in the kitchen or out back the device tries to log on to my neigbours rogers account. The signal is lowest of all surrounding rogers accounts
you can find more by googling "wifi router placement tips" or similar.
The angle through walls, nearby appliances, etc can make a big difference.
Something else you might try if your neighbour is willing is to compare the signal strength with a direct line of site to your router and the neighbour's router(for example 10 feet away and no walls). If the signal strengths are more or less the same it would suggest you might be able to improve your wifi signal by adjusting your router's location.
There are some good free utilities for measuring wifi and cell signal strengths. I use Network Signal Info from the Google Play Store.
Is this a cell phone that is running via wifi or a cordless 2.4 phone that is attempting to connect to the neighbors
modem or router, which would be rather strange? The Hitron modems are not known for their wifi performance.
You could reposition the modem which would require a cable connection somewhere else in the house, or decide to run the modem in Bridge mode with a good router behind it which will provide better wifi coverage within your home.