I'm not sure exactly what you mean - do you mean you lose network connectivity when another device connects, or just that you don't get the same IP address every time you power up your laptop?
So.....I'm on pprune (of course!) happily connected and surfing the future and as soon as someone else comes home, their device(s) seem to command priority from the router and a little box pops up on the screen telling me, as it's already a 'fait accompli' , that my address has been changed to (e.g from ...0.2 to ...0.3 etc) and that's that. If I recall correctly I cannot continue using the router until I click the azure blue 'agree' button. Why should my device be of less priority and the others more ? I know my place, but really!
SHJ