Working on an iPad, I cannot see 1940 Census images for Alabama. Tried a few pages of various districts, but no images. Addtl info: when I tap and attempt to move a (non-existent) image, the screen behind the image screen scrolls.
The developers for that website (https://1940census.archives.gov/index.asp) have said that that is a known issue. Have you been able to access the images you need? If not, please let us know what you're looking for and we will connect you with someone who can help.