My 19 year old is perfectly self sufficient and often looks after herself when we are away for the weekend.
The problem is that they are constantly rude to us, demanding of things, wanting things done right now, not doing the one chore we have set them.
It feels like it's all take and no give and if we try and talk about it we just get shouted at.
I have now asked them to move out because I just can't take the atmosphere anymore and being so disrespectful. Also I am sure they can behave better as they are perfectly nice when friends are round.
This has been the case for around 3-4 years now, with ups and downs. They do suffer with mental health and possibly autistic and although that explains some of the bluntness I feel it doesn't excuse it.