Hello
Hmm, this just started and you haven't recently moved or anything? Barking is not easy to fix, but all I do is immediatly correct it when it happens. I go to the dog and tell them "NO", clap my hands once loudly or gently put my hand around their muzzle (unless there's actually a good reason for it like someone knocking on the door). Some people put coins in a tin can and shake it. It's usually something you have to "snap them out of" then you can distract them elsewhere.