Relational custom field to product variants on collection causes validation errors on save in new dashboard

[robinjoh]

Describe the bug
After the latest update to vendure 3.5.3 i can no longer save my collections because i have a relationship custom field defined to a list of product variants. Getting this error message:
GraphQL Request Error: Variable "$input" got invalid value { includeInNavigationMenu: true, urlKey: "pinnharv", urlPath: "lastmaskin-traktor/jordbearbetning/pinnharv", oldUrlPaths: ["pinnharv"], isPrimaryCollection: true, featuredProductsIds: [], metaTitle: "Pinnharv för traktor", excludeFromRelatedProducts: false, featuredProducts: [] } at "input.customFields"; Field "featuredProducts" is not defined by type "UpdateCollectionCustomFieldsInput". Did you mean "featuredProductsIds"? .

Seems the input is expecting the ids of the featured products that you pick in the list but they dont seem to be passed to the backend. Possible that an empty array must be passed in?

My custom collection field is defined as this:
export const FeaturedProductsField: CustomFieldConfig = { label: [ { languageCode: LanguageCode.en, value: 'Featured products', }, { languageCode: LanguageCode.sv, value: 'Utvalda produkter', }, ], description: [ { languageCode: LanguageCode.en, value: 'Products in this list are considered "featured" and will be prioritized to be displayed when showing products in carousels in the storefront.', }, { languageCode: LanguageCode.sv, value: 'Produkter i den här listan räknas som utvalda produkter och kommer prioriteras när de visas i frontend.', }, ], name: 'featuredProducts', type: 'relation', entity: ProductVariant, list: true, ui: { component: 'product-selector-form-input', }, };

So currently this is completely blocking us from saving any collections in the dashboard and if it is not fixed as soon as possible we must downgrade. :/

To Reproduce
Steps to reproduce the behavior:

define a product variant relationship on collection as i have pasted above. Then create a collection and try to update it. You will receive a validation error.

Expected behavior
Collection to be properly saved.

Actual behavior
Validation error.

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Error logs
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Environment (please complete the following information):

• @vendure/core version: 3.5.3
• Nodejs version: 24
• Database (mysql/postgres etc): PG
• Operating System (Windows/macOS/Linux): Linux
• Browser (if applicable): chrome
• Package manager (npm/yarn/pnpm): yarn

Configuration
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Minimal reproduction
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Workaround
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Additional context
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• When did this issue start occurring? After upgrading to vendure 3.5.3, latest release.
• Does it happen consistently or intermittently? Consistently.
• Any recent changes to your setup? No.