It appears the DLP Chrome extension doesn't seem to like this. Where it is effectively not carrying out the redirect, bu just returning back to the redirect page, where it tries again but without the URL ( makes sense as this is rendered server side).
To the user, the URL appears to remain the same, and the server is registering a redirect on the first attempt but obviously not carrying it out.
Has this been seen before, am I missing something obvious?
Tested this with and without DLP Chrome extension, doesn't redirect and does respectively.