If you want a CSV file use the Export-CSV cmdlet, don't use redirection or the Out-File cmdlet.
You're not going to export all the properties of the ADComputer object if you only select two properties.
Post an example of an incomplete distinguishedName.
If you replace the "-filter *" with just the name of a single computer, and you don't redirect the output to a file, is the "correct" distinguishedName shown on the screen?