UPDATE: Lemmy v0.19.0 fixes this issue.
A lot of people are having issues with image uploads.
TL;DR, this is an unfixable Photon issue caused by a Lemmy issue
Right now Photon does authenticated requests by sending an authentication header with the jwt of your account. This works for most stuff, except image uploads. Image uploads require a cookie, which can't really be done client side.
As a workaround, Photon will proxy your image upload to the photon server. (nothing is tracked, you can see at hooks.server.ts) However, this means all requests come from the same IP- which can cause rate limits
It is caused by This GitHub issue