I figured the same, but according to the Pihole dashboard my queries are spread evenly across the day (with natural dips at night due to lower activity).
However, you have pointed me in the right direction. I have another issue that I need advice to solve. I've posted it here 47388
I'm getting a lot of "not found: 3 (NXDOMAIN)" errors. Which I'm guessing could result in the rate limiting?