Imgur now blocks several VPNs and have issues loading embedded previews in several fediverse platforms. So instead of using imgur, you could use one of the following alternatives for uploading your images.
https://postimages.org/
https://imgbox.com/
https://imgbb.com/
https://www.imagebam.com/
Click on the image icon on the side of the alt text and you will see the image. If you want, you can set images in posts to autoload from settings.