Item format custom HTML is not valid.

The core of drupal is 10.2.3 and webform is 6.2.2.

Add the following content to the source, then go back to Elements and click the "Edit" button of test_field_1, and then directly click the "Save" button in the pop-up window on the right.
You will see the error message:

Item format custom HTML is not valid.
SQLSTATE[HY000]: General error: 1267 Illegal mix of collations (ascii_general_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation '=': SELECT "name", "data" FROM "config" WHERE "collection" = :collection AND "name" IN ( :names__0 ); Array ( [:collection] => [:names__0] => core.date_format.Y年 )
4 errors have been found: Item format custom HTMLItem format custom TextItems format custom HTMLItems format custom Text

modi:
  '#type': wizard_page
  '#title': modi
  '#next_button_label': Next
  test_field_1:
    '#type': date
    '#title': test_field_1
    '#datepicker': true
    '#date_date_format': Y年
preview:
  '#type': wizard_page
  '#title': preview
  '#prev_button_label': PreView
  test_field_2:
    '#type': computed_token
    '#title': test_field_2
    '#template': '<span>[webform_submission:values:test_field_1]</span>'
actions:
  '#type': webform_actions
  '#title': 'Submit button(s)'
  '#submit__label': Save