I had a similar situation with a loved one. Out of the blue for the first time ever in my life they started to get angry with me, calling me derogatory names and told me to leave the assisted living facility. I didn't know what to do so I asked the staff and people I knew. I got different answers on what to do so I had to decide to do what I thought was best. The next time I went they got angry with me I simply left. I didn't go back for about a week, after going almost daily, and they were happy to see me and never got angry again.

So talk with professionals who know about dementia behavior and others whose opinion you value. Then you will have to make the best decision.