Files created on one Chromebook not available on another

My students are crating videos in Adobe Express. Two of them had to use "loaners" I have in my classrooms while theirs were out for repair. Now that their Chromebooks are back, they can open their Adobe accounts on their own Chromebooks, but the files they created on the loaners are not there. I thought all the work was cloud-based!  What did I miss? These students need to be able to finish the job on their own Chromebooks which they take home. Thanks.