The same experience happened to us!
Three years ago, we moved from Illinois to North Carolina to be close to his son. It hasn’t been that easy with all the changes we made: environmentally, the weather (pollen), doctors, shopping, driving, everything and everyone is different. I really started to notice his Dementia was getting worse and he did too, so we went to a neurologist. He was given the strongest meds for dementia but it hasn’t helped much. So to be sure the diagnosis is dementia, he is having a brain scan next week. We went to know what we are dealing with and decide what to do for him next.