I recently conducted a DNA test on ancestry.com and I received a strong match with a guy I don’t know . 758cms across 23 segments longest segment 86cm. He is 57 years of age and my father is 70 and i am 44yrs. My sister also on Ancestry and comes up as full sibling to me and high match with the guy -590cms . Also my 1st cousin is on there(fathers sisters daughter ) shows a lower marking 495cm ,22 segments (longest segment -77cm)

My 1st cousin doesn’t show up as a shared match to the guy but my sister and I do - quite high. Is this potentially my half uncle ? Dads half brother ?