If I have photos in my camera roll on my iPhone or iPad and go to Facebook and select images I can choose the order to load them onto the post I create.
if, instead, I have a set in Lightroom (I don't use the Camera Roll within Lightroom that has recently become available) and I select them and Share to Facebook the resultant post is in random order.
For example, I have just been to an event, created an album for it, then edited the images. I selected them (they are in chronological order) and hit Share and chose Facebook. The results are no longer in chronological order on Facebook.
I would like them to be able to be posted in either the order I have selected them or in chronological order.