I use a heirarchical system of keywords and if I have a photo of a bird I use FAUNA/BIRD/name of bird. If it is a mammal I use FAUNA/MAMMAL/name of mammal. LR Mobile only picks up the first two levels and disregards the rest (the most useful!). Is it possible to display the third level in LR Mobile please.
Thinking that it may be because of too many levels I removed one tier (FAUNA) of the hierarchy and have left it overnight to see what happens. I presume synchonisation has happened, but find that the tier I have removed has not been synchronised and that in two albums of 264 photos on LR Mobile one photo has the third level i.e the name of the bird.
The link you provided shows that this has been an ongoing discussion for years, so please Adobe make it work!