Thanks for replying @DanPatterson!
Using CAD to Geodatabase caused ArcGIS Pro to crash.
I discovered the issue was due to the units in the DGN file not being set to meters.

Changing the units to meters resolved the problem for me.

Here is the script for Microstation V8 in case someone else encounters this issue.
Public Sub changeunit()
Dim fol As Folder
Dim fil As File
Dim fso As New FileSystemObject
Set fol = fso.GetFolder("folder-path-to-DGN")
For Each fil In fol.Files
Set dsg = Application.OpenDesignFile(fil.Path)
CadInputQueue.SendCommand "set units meters"
CadInputQueue.SendCommand "FILEDESIGN"
Next
End Sub
But still ArcMap automatically assigning the units and ArcGIS pro does not.