Unable to upload photo for photo post

Ever since I've switched to lemm.ee, I've been unable to upload a photo when submitting a photo post. I've tried in Voyager, Sync, and also just in my browser and received some sort of general error each time.

Is there a known reason for this? I don't submit a ton of photo posts, but the timing of it made it seem like it might be linked to switching to a different instance. Are native photo posts disabled on lemm.ee, or is it just me having issues?