It sounds as though nothing is actually being lost but for some reason the sheet isnt displaying them properly. I'd make sure you dont have any add-ons or browser extensions that could be causing issues and have a look over the generic support info roll20 usually gives out - <a href="https://wiki.roll20.net/Solving_Technical_Issues" rel="nofollow">https://wiki.roll20.net/Solving_Technical_Issues</a> Specifically, and particularly if you can reproduce the issue every time, step 4 (console logs) might hold some insight into something going wrong when the sheet is reloaded so load up your campaign, open the console as per the instructions in the link, then go through the process of creating a new character, adding some data to the inventory, and then reloading the campaign to see whether the data is still shown. If it's not I'd hope the console might give us some clue as to why. Don't be giving out your username and password to anyone though! If you want, you can PM me the join link from your campaign and when I have time I'll join the campaign to see if i can see the same issue (you'll need to assign me permissions to a character or two once i've joined).