Plugin dont work for me

Hello,

I created a form with a conditional group and a rule.

In your formtester it works fine, but for some strange reason not at my end.

<label> Bearbeitet von*:</label>
[select* mitarbeiter include_blank class:form-control "***" "***" ] 



<label> Kundennummer (Moco)*: </label>
[number* kundennummer class:form-control]



<label> Auftragsnummer (Moco)*: </label>
[number* auftragsnummer class:form-control]



<label> Weiterverrechnung*:</label>
[radio weiterverrechnung use_label_element class:form-control default:1 "15%" "0%"] 



<label> Kaufdatum*: </label>
[date* kundendatum class:form-control]



<label> Upload Rechnung*: </label>
[multilinefile* upload filetypes:png|pdf|jpg class:form-control]



<label> Infofeld: </label>
[textarea infofeld x5 class:form-control]



Zeitraum:
[radio radio-430 use_label_element default:1 class:form-control "einmalig" "periodisch"]


[group periodika]

Periodika:
[radio radio-431 use_label_element default:1 class:form-control "Jährlich" "Monatlich"]

[/group]


<label> Produkttitel/-beschreibung*:</label>
[select* produkttitel include_blank class:form-control "Wordpress Theme" "Magento Theme" "Plugin WordPress" "Plugin Magento" "Domain" "Webspace" "Hardware" "Stockfotos" "Druck" "Lektorat" "Fotografie" "Sonstiges"] 



<label>Weitere Informationen zum Produkt:</label>
[text sonstiges_text class:form-control]




<label> Freigegeben von/autorisiert von*: </label>
[select* freigabe include_blank class:form-control "***" "***"]


[submit class:casc-button class:casc-button-black "Senden"]

The rule: show [periodika] if [radio-430] equals “periodisch”

But no matter what i do the group wont show.

Any idea what could prevent this?

thx for the help.

The page I need help with: [log in to see the link]