Lightroom Mobile Collections- Files Upload Out Of Sequence

After I rename and sequentially number all my RAW files (starting with 01_customname.cr2  or 001_customname.cr2), I perform all my edits and then export them to a sub-folder as small jpg files.  I then create a collection from that folder of files and then sort the filenames in ascending order (ex: from 001- to 999).  Then I sync with Lr Mobile.  The problem is that almost ALWAYS... the thumbnails in the mobile collection display out of order/sequence.  And there is NO WAY to sort a gallery by FILENAME (and don't get me started with my ongoing frustration regarding displaying filenames below images by default).

From the collection online in Lr Mobile, the small sort-order icon in the top-right corner sorts ascending/descending... HOWEVER, I think it is ordering the date/time CREATED.  So, if you create files 001-999 and then change the exposure of image 555, it may appear as the first or last image in the order.

This is maddening, Adobe.  PLEASE give us a more robust way of sorting images via Lr desktop/App or from within the web collections.