Advanced File Uploader

I am using Caldera Forms (V 1.6.1) to allow users to upload images to the Media Library. After upload, I would like to re-direct to a page that shows the images that have been uploaded.
If I use the basic File field type, my variable (value %image_1%) is correctly updated with the file location and passed across to the redirect page. However if I use the Advanced File Upload, what is passed across is literally %image_1% – ie the ‘variable’ value is not updated with the file location, but passed as a piece of text. I have ensured that with both upload fields I am saving to the Media Library and I have checked several times that all the settings of the two versions of the upload field are identical.
I could use the basic File upload, but I preferred the Advanced Upload interface, so it would be good to get this working correctly.