Can't help you. I'm basically at a loss myself. Got mine only half a year ago though, but apart from growing a leaf that is still not fully grown and a couple of roots, it hasn't done much. How large is yours? It looks so much bigger than mine, but maybe it just looks that way on the picture. Our plants got roughly the same number of leaves.
I also keep mine in bright light and temperatures have probably been hot here in the summer months. Mine is mounted. Probably not such a good idea, because it had a bit of a dry spell and did suffer from the dehydration. I'm considering putting it into a pot like yours.
Hopefully somebody will give us some tips and advice. I'd so like to see these flowers in real life. I've only seen pictures up to now.
My hunch is that it is not getting a large enough temperature difference between day and night. Some forms of Sarcochilus hartmannii come from New South Wales, Australia, which is in the southeastern portion of the Australian continent.
You can search the climate of NSW online and see what they would go through if they were in the wild.