Phone calls suddenly stopped. Any advice?

My mother moved to ALF a month ago due to cognitive decline from stroke a month before that. She had mild dementia prior to stroke but significant decline after. She has been anxious and sad both before and after the move to ALF due to the stroke. For the month she has been there, she calls a couple times in morning and many times in afternoon and evening with confusion and anxiousness. She started Zoloft on Saturday. I didn’t hear from her at all Sunday or Monday. Could that be med so quickly? Or coincidence? Or worsening dementia? She also has heart failure/afib/SOB. Could be she’s sleeping due to that. I can ask her or facility. But just seemed so sudden that the calls stopped. I’m relieved and confused at the same time about it.