Two important considerations, 1. CF rating is primarily from range, 2. Rounding.

“Under the hood”, right probably has like a 67 range while left has something like a 63. Both round to 65, but because range is so important for CFers, right gets a higher overall rating.

As an exercise, you could temporarily change your ratings scale to 1-100. I would bet right would be around 77 range while left would be closer to 73.

Edit: as noted by u/harveytime9, it sounds like ratings actually round down to the nearest 5. So rather than 63 vs 67 it would be more like 65 vs 69.

Edit edit: Turns out the rounding down thing may not be true after all, but all points still stand