I downloaded openmediavault_5.0.5-amd64.iso from https://sourceforge.net/projects/openmediavault/files/5.0.5/
The file fails to match all three hash values (MD5, SHA1, SHA-256) using http://onlinemd5.com/
Has the .iso been compromised?
Edit: I just downloaded and check version 4.1.22, and it also fails hash checks.