Modem drops multiple times

Hi all. I am a Comcast customer who has to  use VoIP. This put me in a tight spot. On 2/15 I gave up I had to buy another one but of tthe same model ARRIS TM822G.All went fine for a few days then it's going at it again. Reset is the norm anymore.The question is could there be somthing wrong with my Router?

It is a 4 year old Linksys WRT1900AC and have experienced some problems with it, such as slow speed not picking up the 5Ghz. Since I now have a New? Modem should I get another Router but smaller I now live in a two bedroom house 1 floor the 1900 is now overkill. I did spen about an hour with the Linsys Tech. Things got better but not where I should be. My plan is 200Mbps DL 30Mbps UL

This all went south I get 12Dl 3Ul

Thank you