My iCloud Photo Library seems to be broken

iCloud Photo Library on my iPhone keeps reminding me that it’s been 10, 20, 30 days since I’ve last uploaded photos. But when I visit the Photos area of the Settings, here what I see:

It’s attempting, over and over again, to upload the first of 91 photos. As you can see, the upload fails, and starts over.

I have no idea how to resolve this, other than just disabling and re-enabling the whole thing and hoping for the best. But if I did that, would I end up re-uploading my entire photo library? Sigh...