Lost hours of work on a map

I had been working on a Map for several hours today and didn't experience a connection loss banner I had exited and re-entered the game map "N. Complex B1" a few times today, but I hit a connection loss banner at around 3pm EST and things seem rolled back by several hours. I had been placing a large amount of map tiles down in a single area of the map, but otherwise I'm not sure how to reproduce this. I figured I'd wait out the banner and get back to work later, but upon returning to the game, I had lost over 6 hours of work. Please let me know if there is a way to manually save my work in the future and if my work from today is recoverable. I'm using a Windows 10 PC and browsing on Chrome 61.0.3163.100.

Hi Drespar, I performed a rollback, but I could not recover any lost work. (I have since rebuilt the map, and better this time around.) I did want to mention that I had Roll20 signed in at my home PC and was making edits on my work PC. Just extra info in case I created conflicting browser sessions. Also, I may have added too many token objects before my data loss on the 3rd of November. Thank you for following up, I hope this info helped in some way. Please let me know if you need additional information.