Check for sleep apnea. The apnea intrupts sleep because you stop breathing and makes you sleep longer. On top of that your blood O2 drops way down which accelerates dementia.
I clearly have some sleep apnea issues. I have a Fitbit Charge4 to monitor my sleep SP02. I've found that 1000 mg of vitamin C and a 1000 mg chaga tablet at bedtime will boost my SP02 to 94 to 97 percent. If I skip that part of my bedtime preps, the sleeping SP02 runs 91 to 93 percent. The Charge 4 also tracks sleep phase including awake, rem, light, deep. A sleep quality metric is calculated. The recorded values of sleep start/end time are pretty accurate. The resting heart rate is also calculated along with heart rate variability and breathing rates. Useful inputs.