Spring boot validate each string in a List (kotlin)

I'm struggling with validation in String Boot.

I have the following class in Kotlin:

class ListBlock(
    @field:Size(max = 5)
    val style: String,

    @field:Valid
    @field:Size(max = 10)
    val items: List<@Size(max = 50) String>
)

@field:Size(max = 5) on style works fine by having size > 5

@field:Size(max = 10) on items works fine by having more than 10 strings in the list

I don't get any errors if one of the strings in the list has a size larger than 50 characters.