It is pretty intuitive that increasing the height or distance of an object and also increasing the mass of it increases the gravitational potential energy (GPE).

Basically the question is asking, with regards to this equation $$U=-\frac{GMm}{r}$$ if you increase mass, this makes the $U$ more negative whilst increasing the distance makes it less negative (closer to 0). This is confusing because even though both increasing distance and mass will increase "GPE", it's not reflected in the output number of the formula, $U$.

Could someone help me understand that although both increase the stored energy, they change in $U$ differently?