I have a process where for each input file, I must create 2 output files. For some reason, I seem to be unable to use more than 1 db:replace in the same function. I have tried pieces of code separately to ensure that every individual piece works. They do work. For your information, I have included my tests as comments after the function.

(: param $lang is the desired target language of the translation :)
declare %rest:path("/admin/convert-to-xliff")
   %rest:GET
   %rest:query-param("lang", "{$lang}", '')
   updating function admin:convert-to-xliff($lang as xs:string){
   (: Src language is assumed to always be en-us as per business rules:)
   let $src-lang := "en-us"
   for $x in app:open-db($src-lang)
   let $xliff-stylesheet := app:get-translation-xliff-to-xsl()
   let $skeleton-stylesheet := app:get-translation-xliff-skeleton-xsl()
   let $params := map {"lang-to" := $lang}
   let $target-uri := replace(base-uri($x), $src-lang, $lang)
   let $target-skeleton-uri := replace($target-uri, '.xml', '_xliffskeleton.xml')
   let $xliff-doc := xslt:transform($x, $xliff-stylesheet, $params)
   let $xliff-skeleton := xslt:transform($x, $skeleton-stylesheet)
   return db:replace("Translated-units", $target-uri, document{$xliff-doc}), db:replace("Translated-units", $target-skeleton-uri, document {$xliff-skeleton})
};

(: db:replace("Translated-units", $target-uri, document{$xliff-doc}) --- Creates the expected files in the expected location :)
(: db:replace("Translated-units", $target-skeleton-uri, document {$xliff-skeleton}) --- Creates the expected files in the expected location :)
(: concat($target-uri, ' --- ', $target-skeleton-uri) --- remove decl as updating function to test this, both paths are set :)

I tested the $target-uri and $target-skeleton-uri as strings, and they both get the expected values as string outputs.
The db:replace for each of them works individually.
However, when I try 2 db:replace, the second one return an error: [XPST0008] Undefined variable $target-skeleton-uri.
If I reverse the db:replace, the 'new' second one gets the error: [XPST0008] Undefined variable $target-uri. Therefore, it looks like it has nothing to do with the fact that the variable is undefined.

Any clue?