If you expand the images in the spoiler you can see screenshots of me trying your suggesting about the cache. I cleared the browsing history (all of it, not just cached images and files) and it still doesn’t work, and tried incognito mode like you did, and it worked a bit because I could at least see the image if I opened it in a new tab. I’m adding the info about adblocker on/off because that’s the only ‘fix’ provided by the admins on Mastodon and in the FAQ. Since that’s the first thing I tried to disable, it’s obviously not that hence me coming here to ask for help. I’m trying to be as complete in my info as possible so the person who has to solve it hopefully has the information they need :) and as I’m not that much of a computer person, I don’t know what information is most important to share.