Nested conditions not working

Hello, have the following code and don’t know why the second group is not showing when cklicking “three”

[checkbox MEMBERSHIP-DISCOUNT “YES”]
[group DISCOUNT-CONDITIONS clear_on_hide]
[checkbox DISCOUNT-CONDITIONS exclusive use_label_element “ONE” “TWO” “THREE”]
[group OTHER-REASON clear_on_hide]
[text DISCOUNT-OTHER-REASON placeholder "this is why"]
[/group]
[/group]

show [DISCOUNT-CONDITIONS] if [MEMBERSHIP-DISCOUNT] equals “YES”
show [OTHER-REASON] if [DISCOUNT-CONDITIONS] equals “THREE”

Formtester URL : https://conditional-fields-cf7.bdwm.be/form-tester/?hash=4327d73d2723685e1842b8f6c05b4c18

Would be happy for any hint. Thank you!