Sync won’t complete for Lightroom mobile

Sync will not complete from my mobile phone Lightroom app. I've synced no problem many times before. I have no problem on the computer. One file from my phone just won't upload. I tried deleting it, duplicating it, and re-uploading. Same problem. I updated the app. I'm not willing to delete everything for one file. I have a very large number of files on CC. I'm extremely disappointed that as a customer paying the ridiculously steep price for the Adobe suite that they don't offer support and I'm forced to post this here.