I'm using Damus on iOS
Discussion
Here you can confirm which image uploader you are using. You can change if one doesn’t seem to be working.
You should also confirm what file you are trying to upload, is it parfer than 25MB?
All tests are working and actually with our new CDN upgrade things are faster than ever, globally!!
https://nostr.build/av/1accdc8dd75d8eebcf0e0a21dc6e44c1c23b9b0e5dd93004344483f432ef83a5.mp4
21.2 MB JPEG. All I see in your attachment is a dark, changing, blurry image
Another test image from Damus..
I’m thinking it’s your connection.. 
So I can upload the same photo to Threads rn but not here? But it's my connection?