When creating dashboards I tried selecting a duration of 168 hours (1 week). The dashboard allowed me to select this duration and correctly showed the data. After closing and reopening the dashboard I noticed that the duration was now just 68 hours. It appears that the duration is only allowed to be 2 digits when saved even though it can be put in successfully as 3 digits.
This is a glitch that I was able to repeat multiple times and also repeat on another person's computer.