Anyone have tips for dealing with or relieving sundowning & insomnia after a hospital stay?

My uncle just returned home after a two week stay in inpatient rehab. He had dementia already, but he had a stroke which affected his left side in early February. He has been more confused since the stroke, but I am hoping a lot of that is due to being in the unfamiliar environment at the hospital for several days. His doctor in the hospital also had him on lorazepam for mild agitation, but his primary care physician has taken him off of that because he’s a fall risk due to the stroke, and he’s normally not anxious or agitated. He is content during the day, but at night his caregivers say he’s refusing to stay in bed and not sleeping at all…. which is keeping my sweet aunt, who also has dementia, up all night too. He was a good sleeper before the stroke, and he did not have any sundowning issues. I was just wondering if anybody on here had experience with this type of post-hospital stay or post-stroke behavior changes?