Dashboard randomly displaying incorrect data

I built a dashboard to show hourly instrument capacities based on a term list. The term list consists of the TestInstrumentID and the number of tests that instrument can perform in 1 hour. The calculation works correctly and the data is accurate but periodically if you go to check the dashboard the percentages all get changed to 100% across every hour. If you check it later or add an additional site to the filter then the percentages correct themselves. I don't know what's causing this or how to troubleshoot it because it does calculate correctly but is not consistent.