Unexpected behavior with respect to attachment visibility vs attachment_decay state

Summary

After setting up a self-hosted server, I noticed that media attachments all carried a notice indicating that they would expire in 3 years. This notice was a link which led to an HTTP 404 response, thus I do not know if this is intended behavior or a bug. "attachment_decay_enabled": false was added and this removed the notice from the attachments, both the ones that were created prior to disabling decay, and on the newer additions. What we noticed was that if a new user joined the server, any media that was uploaded WHILE decay was in place, but BEFORE the user joined, was blurred as if a spoiler tag was applied. These users were able to see new content that was added after they joined the community, but not any prior. After disabling attachment_decay, new users had the same experience in that they were unable to see media that was both 1) attached prior to the removal of attachment_decay an 2) added prior to the user joining the community. The big issue is that this affected not only images attached to messages, but also emoji, profile images, the server banner and icon, etc.

Steps to reproduce

1. Pray
2. Install self-hosted server
3. Log in, set up a community.
4. Set icon/banner for community.
5. Add some emoji
6. Set your profile image.
7. Post some images in a channel.
8. Have someone else join the server and verify that media created in steps 4-7 are blurred or inaccessible to them.
9. Have new user perform as many of the steps 4-7 as necessary.
10. Disable attachment_decay and repeat steps 4-7 with either user.
11. Have a third user join the community.

Have third user verify that all media created prior to removal of attachment_decay in step 10 is unavailable, and that the media generated in step 10 after removing attachment_decay is available. This might be intended behavior, but it probably should not apply to the server icon/banner, profile images, and emoji as that creates a confusing situation for new users to the community and it is behavior that is completely unexpected for the owner of a server/community.