That ***** that Dropbox is not cooperating now.
To keep moving forward, and not hold up progress on getting things put away and organized, can you go with a work around?
What if you use Excel in Onedrive to hold the info for the QR codes? The QR code would reference to a unique number that you'd enter in column A in excel, 0001, 0002, 0003, etc. Then columns B, C, D, E can be further details for location, shelf, bin, and then a list of the contents.
Excel in Onedrive should be available on both your phone and computer. So you could have it open on your phone, and enter the info as you put stuff in a bin and put it away. Since it's Onedrive, you can also easily open it on your computer, and enter further details and descriptions.
Is it an ideal solution... probably not, but if it allows you to move forward, that would be a win.
The other nice thing about excel is that you can search for key words, and there's no limit on number of lines.
I use a lot of Excel sheets for leading weekly meetings for work stuff, and 10 years later it's still my preference vs other tools.
I know from experience that you can have multiple people in the file at the same time making edits, and it works. For an upcoming meeting later this week, we'll have up to 300 people in excel online all making edits at the same time and it works. So you could easily have it open on your computer and your phone at the same time.
Just my 2 cents worth, hopefully you can move forward.