Clicking download original link upper right on document isolation viewer does not download original file. After clicking the link, the page is redirect to the document isolation viewer again. Is this expected behavior?
Document Isolation rule needs to be enabled with a separate download profile to allow the download.
To Just View Files in Document Isolation:
If your purpose is only to view the File Types in Document Isolation Viewer and not to Download the File Type (Also if you do not want to create new rule), then based on your requirement(source/destination), you can enable default Document Isolation Rule as below.
Important Note: You will only be able to view the file type in Document Isolation viewer if you change File Type to "View" by editing rule in Document Isolation Download Profile.
Note: By Default File Types are either set to "Scan or Block".
To View and Download Files in Document Isolation:
If your purpose is to Download File once it is redirected to Document Isolation Viewer and then click on top right corner and click on "Download Icon" to download file.
In that case, You need to create separate rule with new Download Profile in that rule ( You can use built in "Primary Profile" or create new one if you would like)
If you do not create separate rule then Download will not work and you will notice it just forms loop when click on download icon and nothing happens.
Below steps to be followed for Download to work correctly when in Document Isolation Viewer.
you can leave default Document Isolation rule at the Top and the New Rule created below that one.
Now the way policy evaluation will work is , it is going to match the New Rule for Document Isolation which you have created (which has Primary profile or new profile) and that will match the file type verdict to "view". this will redirect you to Document Isolation Viewer (since you have view setup for that file type). Now when you click on Download Button, it will match the Default Document Isolation Rule (since default document isolation rule has "destination field" setup which is URL for Download). Based on the Verdict in Default Document Isolation Rule (either Scan or Block), it Scan then it will allow download and if Verdict is Block, it will Block the Download.
Important Note: Issue happens if you do not enable both the rules, you just enable new rule which you have created (assuming you do not require the default Document Isolation Rule). That is reason you need to enable both the rules.