a mixed blessing
A situation or circumstance that has both positive and negative results. My new promotion will be a mixed blessing for my family because I'll get a substantial raise, but I'll have to work longer hours too.
mixed blessing
Something that has both good and bad features, as in Being accepted by the college was a mixed blessing, since she couldn't afford the tuition . [First half of 1900s]
mixed blessing, a
A fortunate occurrence that has some unhappy elements. The OED’s first citation of this phrase is dated 1933, in Discovery (October issue): “The introduction of European influences may prove a mixed blessing.”