Maybe the Dunhams had a cash flow problem... they would have had to pay Barack Sr a pretty penny to pose as the father in order to shield their Commie friend Frank Marshall Davis from possible statutory rape charges and/or even greater FBI scrutiny...
I think that Ann moved back in with her parents to be an instate student. When she originally went to UH in 1960 she would have used the 2277 Kamehameha Ave. address. When she registered for the 1963 spring classes at UH it would have been difficult to prove she had lived on the island continuously so she would qualify as an instate student, unless she used the same address to register again. (which she did) She did receive credit for the courses she took at UW and yet why did it take so long for her to graduate with a B.A. in math unless she didn’t present those credits to officials at UH and had to start almost from scratch towards her degree. With the credits she received her first semester at UH and the credits from UW she should have completed her degree in 1965 not 1966.