When you use the Desktop version...it is not connected to your online account in any way, so the online account will not have a record of anything done with the download version. So it won't show in your Online timeline
You need to keep your own backup copies of your desktop files (OFF OF THE COMPUTER). Both PDF files and .tax2015 datafiles.
While you are thinking of it, open that 2015 datafile right now...check it's E-file status from within that file and save it. That's the only way to make sure the e-file acceptance is permanently recorded in that datafile.