Rx39141

Hello, 
I am trying to fix an internet connectivity issue that has been occurring over the past month, and while doing so I noticed that my nighthawk router had an available update showing in the topright corner of the web interface. Not paying attention, I pushed the update through thinking it was the cause of my issues. Though, once my router rebooted, the firmware version changed from 1.1.0.22 to an older version 1.1.0.16. The update button still shows an available update, but for 1.1.0.16_2. Thinking this was a mistake, I went to download and install the .zip file for 1.1.0.22, but when I try to download the firmware zip, I get a permission denied error. Is this to be expected? 
Furthermore, I am not sure if my router is the source of this issue, as I have no tangible evidence to prove that. Though, I have an Xfinity modem that I have setup into bridged mode that connects to my Nighthawk router. If I take the Nighthawk offline, and set the Xfinity modem back to router mode, the internet connectivity issues stop occurring. This behavior is being seen on all of my devices connected to my network. Any recommendations on what else to try to fix this would be appreciated. Otherwise, I might be out $100 if I am forced to use my Xfinity modem for routing. 😕 
Please let me know if there is any additional info would be helpful with this thread.