Resolving Host Issue

I have been having problems connecting to websites for the past few weeks.  I have had my internet connections/lines checked by the phone company, they have replaced the modem, I have changed DNS settings with ISP help, to no avail.  In Chrome I continually receive a message in the bottom left hand corner saying "RESOLVING HOST ISSUE."  I am not being knocked offline, but my computer freezes up and I either have to reset the modem or close the browser (Chrome or Edge) to start again.  It only seems to be a problem with Wi-Fi, my computer with an Ethernet cable seems to work OK and running Windows 10 and Windows 7 on different laptops.  I have Norton 360 installed.  Any suggestions for a novice?