Had the AC750 for a week and have already needed to restart router to maintain connection?

I bought this extender less than a week ago and at first it worked great. Then today suddenly my phone and computer could not access the internet. They both had full bars from the extender, and could connect to the extender, but could not access the internet. They could both access the internet directly from the router when I moved close enough, however, so I know the problem is with the extender. 

I unplugged the extender, then unplugged and replugged in the router and waited for it to boot up, then replugged in the extender, and everything worked fine. Unfortunatley the router is in my landlords house so I had to ask to enter his house and do this. I don't want to have to do this every five days. Please tell me: is there something else I can do to prevent this from happening again?