Constant connection issues

Since the last time Comcast has worked on the lines by us about a month ago, I've had constant issues with connection and maintaining connection. Some devices will stay connected while others will not until I restart the modem. From laptops, tv, chromebooks, gaming consoles etc. Some websites will work other times they won't. Example being my son needed to do his homework on his chromebook but a website did not load for him no matter what. Other websites were working OK while others were not. I ran a diagnostic on there and it said there was no ipv4 connection and ipv6 was working fine. This will happen with all the electronics in the house. One moment 2 tvs and laptop will be connected and working just fine while another TV or console will not be able to connect and I have to restart the modem. I restart the modem at least 5 times day to be able to connect one device even though other devices are connected and working fine. Same with the websites, I for example can't access my bank account on my laptop until I restart the modem and then the page will load. Other times works just fine and other times will say there's no connection but other websites will run just fine. Theres been no new apps or anything downloaded and i have not messed with my firewall at all for years so everything has stayed the same on that front. Also yes needless to say I have unplugged my router for at least 10 minutes and plugged it back in and yes all the connections are secure and tight. Please help as this is driving me crazy!