As the title says and the video shows, the shader in your first inventory slot cannot be moved to the Vault. It doesn't matter what shader it is, it's only the shader in the first slot. This is basically a non-issue, but it's still a bug, and it might be contributing to other bugs introduced in the latest update (1.2.3 on July 17, 2018), so I thought I'd at least try to bring it to someone's attention.