I don't know for sure, but thinking about how it works for humans I suspect that in many species the hormone levels would be weird for a typical individual of either sex and that might cause infertility. It's usually pretty hard to prove a negative though, I wouldn't be utterly shocked if something fairly basal like a frog might have one set of gametes or the other come out functional.
It's definitely an interesting question. My strong suspicion is that gynandromorphs probably have an intermediate level of sex hormones and even if the organs were properly developed this would tend to prevent fertility but it's not like I've checked.
[deleted] OP t1_jc2i2z0 wrote
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