Check up to make sure that he is well and in particular, has no infections, but if he is clear then it will be progression of the dementia.
Increased confusion in the evening and night is very common and is due to sundowning and this may be what he now has.
Wanting to "go home" is almost universal with dementia in the later stages. If you ask him about what his home is like you may well find that he is thinking about a previous home - usually a childhood home, or a beloved holiday home. Actually, though, wanting to go home is more of a state of mind. He is confused and disorientated and doesnt recognise anything, so he wants to go somewhere where he feels safe, feels he belongs and can leave the confusion behind. In short, he wants his home. No matter that he has lived there many years, the memory has been stolen by dementia and he wants the home he remembers from his childhood.
It is no good trying to argue or reason with them and it will just make them more anxious and confused. Sometimes once the sundowning has lifted and the confusion goes he will remember again, or you can bump-start it by walking or driving round the block and saying "here we are - home!" It doesnt always work, though. Many people use "love lies" and say that they are just staying the night and are going home in the morning, that they are on holiday there or are looking after the house for a friend. Try and find something that will ease his distress and calm him.