My husband was diagnosed with vascular dementia in July 2018. He really didn't start sleeping a lot until about 6 months prior to his death in Sept 2020. My husband however was at home, and didn't need to be sedated for any reason. I would definitely be talking to his doctor to find out what's going on. Best wishes.
The person to speak to is your husband's doctor as s/he would be the one to tell you what meds he's on and if they would attribute to his sleep patterns. Facilities do NOT hand out meds willy nilly; only upon the written orders of the MDs in charge of the patient.
Difficult to say. In order to be in Assisted Living, where many are active and relatively well, able to take part in community, your husband would need to be somewhat calm and peaceable. If this is not the norm for him, there may have been a decision by his doctor to prescribe some medication. The only way to know the answer to this is for the person who is POA (I am assuming it is you) to discuss your Husband's medications with the personnel who are delivering his medications to him, or to the prescribing doctor. Give either or both a call on Monday and discuss this with them. Wishing you the very best.
Best of luck!