Xfinity App & internet problems

Techician determined XB7 was faulty and installed XB8 modem. I had to reconfigure with new wifi names/passwords.  Since that time, my internet consistently goes out at 9pm and does not comeback despite repeated reboots, which means I have no security services as well. The next morning I reboot and it restarts. Also the Xfinity App only shows Overview and Accounts tab. This is now day 5 and I have expended at least 8 hrs online chatting with agents or talking online. Tired of paying for services I cannot access.</span;>