deployment.beta (broken) https://deployment.wikimedia.beta.wmflabs.org/w/index.php?search=FooBar&title=Special:Search&go=Go&searchToken=5o574ab4kc8326k74aq66pdfr
de.wikipedia.beta (working) https://de.wikipedia.beta.wmflabs.org/w/index.php?search=FooBar&title=Special:Search&go=Go&searchToken=e5rar0kjf3h4tyzuxv03m2eva
The search text box field does not appear on deployment.wikimedia.beta for some reason.
We first thought this was due to an interaction with AdvancedSearch, but after disabling the issue remains, also AdvancedSearch works just find on other beta sites.