Cannot passtrough with regex and custom filter

[Tom-Woef]

Summary

I try to pass-trough all jpg files to another external url with regex. Only when the page url return a 404 and a locale

Actual Behavior

Empty content/White page

Steps to reproduce

I create a regex redirection with Source url ^/(.*).jpg$
i check regex
i choose match type custom filter, with a custom filter that checks if is_404 and get_locale = 'nl'
I choose pass-trough
my matched url is http://old.mydomain.com/$1.jpg

When i switch to redirect type (307) and leave other settings it works

Environment

Worpress 5.0.3 Redirection 3.7.2
Chrome browser