A Reverse Sport From Cara Cara Back To Washington Navel?

[Millet]

Cara Cara is pinkish fleshed orange that originated as limb sport from a Washington Navel orange tree that was growing in Venezuela. All Cara Cara Navel trees are derived from that tree.   I have a large 10+ year old Cara Cara tree that produces a lot of fruit.  I noticed this year that one branch on my Cara Cara tree is once again producing orange flesh fruit that looks and taste exactly like a Washington Navel.  I am believing that that branch has once again sported out and returned to its parentage.  All the rest of the tree produces regular Cara Cara type fruit. - Millet.

[Riverland]

Not uncommon at all. A lot of the early trees established here had the same problem, but much earlier. In the race to multiply budwood, some mutant buds were also used that fruited normal navel fruit.
Very unstable mutation.