Duplicate x values
Duplicate x values, i.e. the repetition of the exact same value in the model data within the order statistics of a single point are problematic for the fitting. Apart from the practical problem, this raises questions about the applicability of the bias adjustment.
This particularly happens when precipitation is exactly 0 for particularly dry areas.
The technical level can be addressed by the removal of duplicate data. The scientific level should be addressed explicitly, possibly in the documentation.