In the “group a finals” rows of the Wikipedia pinyin and zhuyin tables I see an “ong” row present in the pinyin table absent from the zhuyin table.
Zhuyin expresses this final with the combination of “ㄨ+ㄥ”, that is like an “u+eng” sound. But this sound, even with the components slurred together quickly, seems to be very different than the “ong” sound from pinyin.
While neither phonetic system is more correct than the other, one of these sounds must be more correct than the other because they are so different. If both sounds are “correct” in that they are the sounds spoken by native speakers, then native speakers must speak distinctly different depending on which table they used to learn.
This is the first functional inconsistency I find between the two phonetic systems. Are there others just as noticeable?
Edit: I see from a recent question that “ㄩㄥ” may in fact be the more appropriate sound for “ong”, but that too sounds very different, so my question remains.