Panel cannot read querys with custom values

Sorry for the confusing title. I’m not sure how to briefly summarize my problem.

I’m trying to migrate a Kirby 2 installation to Kirby 3 and got stuck on a blueprint with a query.
It searches the children of the manufacturers page and saves the uid of the selected entry. In Kirby 2 it works fine.

    label: Manufacturer
    type: select
    options: query
      page: manufacturers
      fetch: children
      value: '{{uid}}'
      text: '{{title}}'

I tried to adapt the code to the new syntax in Kirby 3 and got it to work:

    label: Manufacturer
    type: select
    options: query
      fetch: site.find("manufacturers").children
      value: "{{page.uid}}"

I can select the entry based on the title and the UID gets saved like in Kirby 2. But after the changes are saved, the selection is no longer visible in the panel. I guess, Kirby 3 can’t get the right selection based on the UID.
If delete the last line Kirby saves the page id, and the issue is gone.

Is there an easy way to get this working with the UID like in Kirby 2 or is using the page id the only option?
I rather have “Manufacturer: company1” then “Manufacturer: manufacturers/company1” in my data to avoid redundancy.

My ultimate goal is to get data from the manufacturers page. I used to do it like this:

<?= $pages->find('manufacturers/' . $page->manufacturer())->title()->html() ?>

This is based on the old Kirby 2 cookbook entry about authors. Maybe there is a new way to approach the problem.

Kirby Version 3.0.2

First of all, the example above works for me, no problem to store the UID.

But, it definitely makes more sense to store the ID (URI) instead. Then you can get the page like this:

$selected = $page->manufacturer()->toPage();
echo $selected->title();

This wouldn’t work if you just store the UID.

Thanks for the fast reply.
The UID is getting stored properly to the corresponding txt file. The Problem is, that the panel is not displaying the selection after the value is saved.

I hope this gif can illustrate the issue.

It does actually work, but is quite messy.

I guess I upgrade my code to use the URI instead. It works with Kirby 3 and is the cleaner solution anyway.

Thanks for the heads up.