I manually order collection sets in Lightroom on my desktop. When they sync over to Lightroom Mobile, that ordering does not occur. There should be an option so that Lightroom Mobile collections are ordered the same way a desktop collections
Rikk Flohr, you are a genius! Not for the answer above but for saving me days/weeks of time. As I was looking for the solution to the problem of Custom Order sorting missing from Lr mobile, I tried the sharing thing you mentioned above. Holy moly! You can create a gallery of images and they are instantly hosted on a remote website! I no longer have to create Web Galleries in LR and export and upload them via FTP to my website (so tedious). Thank you Adobe for this incredibly time-saving feature!