Sorry to hear about your difficulties, here are a few things to try.
1) Try using the Duplicate project feature from the Organizer view with the thumbnails for two projects (shown in your first screenshot). The duplicate button is along the top next to the one for the Creative Cloud (two stacked squares). See if you experience the same behavior with the duplicate copies.
2) Try completely powering down the tablet and then power it up and then opening the problematic projects.
3) Try signing out of the Creative Cloud and then back in and then attempt to upload the projects again.
4) Go to All Apps > Settings > Applications, in here go to Manage Applications, select All applications at the top. Find Adobe Proto in the list, in here there is a Clear Data and Clear cache buttons. DO NOT use the Clear Data button (under the Storage section), it will erase both projects completely. Try the Clear cache button one under the Cache section, that one is okay to use.
Let me know if any these help.
Sorry to hear you tried all those things to no avail. When you upload projects to the Creative Cloud it creates a .zip file of the project. If you had successfully uploaded the project to the Creative Cloud website previously through Proto you could download the .zip version on a computer and extract it. The zip file contains the project in HTML format. You can just open https://creative.adobe.com/ in any browser on the computer to download the .zip file.
I'll follow up with members of the development team to see if they have any additional suggestions. I don't know how complex or how much time you spend creating the project originally but sometimes just recreating the project can be a solution in some cases, especially if the original was not a large time investment.