For no apparent reason I suddenly found that I could no longer browse via duckduckgo or Google (but could through Edge!). The on-screen response just informed that the sites were not available. I had no idea what could have caused this but a Microsoft fault search identified it is a DNS problem. I prefer to use the duckduckgo and need to resolve the DNS situation. Is this a Firefox problem, and if so, how do I fix it while still maintaining security?