The reason you are seeing double or triple is because you're using SUM and you have two or three rows for the same Circuit ID. For example, for "BDO CM RECTO 10Mbps", if you view the data, then click on "Underlying", you'll see there are two rows, so the sum is 20 rather than 10. If you have three rows, you'd get triple the value.
One way to fix this is to use MIN instead of SUM. Since all rows for the same Circuit ID should have the same value, you can use MIN or MAX and the result would be the same.
Thanks Jeff! I will apply your solution. I'm not sure if using Min or Max will also result to correct values if there are multiple circuits with XX Mbps values per customer in the future.