If you have insufficient permission you shouldn't have seen data from the time the backfill was turned on. Can you check the source index (where the raw data is coming from) for the KPI to see if you have data for the last 7 days?
I've checked the results from the KPI, creating a timechart with span=1h and I see the data in the last 7 days. There is only 1 row on the results of 1 of the days where there is no data, but the rest contain results. What else could I check?