Mode test - Date list restriction not applied

Problem/Motivation

Use a date list field in a webform, with a restriction: my case 2018:2023 ( and with only select month and select year ).

In "classic mode", the restriction works like a charm see first capture
In "test mode", the restriction is not applied, the range is from 1970 to 2023 (second capture). So the restriction is not respected.

We used Webform 6.2.2