Photo uploads dates from iphone are off by 20+ years

Hi Hannah - thanks very much for your reply.

I wasn't sure what you meant by manually uploading them, but here's what I've tried:

First, I removed the offending folder from Dropbox, by dragging it from the Dropbox folder to my desktop and telling Dropbox to delete it for everyone. Then I removed the metadata for some of the files, and dragged them back into the Dropbox folder - but they were still shown as being from 2037. I deleted the Dropbox cache from my PC, and I logged out of the mobile app and logged back in. None of that worked, and that's when I posted my original message. I restored the original folder to Dropbox via my web browser.

Just now, I have again removed the folder from Dropbox in the same way. Then I went through all the subfolders and deleted the metadata. Then I went to the Dropbox site through my web browser (Firefox) and uploaded the whole folder that way. (There are 2,500 items.) When I open the Dropbox mobile app, in the Photos tab, most of those photos are still shown as being from 2037. But it does seem to have worked for a few files - mainly jpegs that were altered in Photoshop, or via an app, or which were taken by someone else, or png screenshots.

There is another folder with the same problem, photos that were sent to me by someone else, and which are dated 2053. For these, I tried something else: I selected "Make available offline", then deleted the metadata for the Date taken, and waited for Dropbox to update. This didn't work: when I look in the Photos tab of the iPhone app, they are still shown in 2053, and when I select one of the pictures, it says "You have saved a new version" and gives me the option to refresh it. I do that, but it doesn't change anything - it still appears in 2053, even though the file info does show that the 2053 date has been removed. I'm pasting a screenshot below.

Is there anything else you could suggest?

Thanks in advance

Katie