Oliver, add the client-side JS call XSP.allowSubmit()
to your button in order to allow new submits after pressing the button:
<xp:button id="button5" styleClass="btn btn-sm printbutton" style="display:none">
<i class="fa fa-print"></i>
 
<xp:text>
<xp:this.value><![CDATA[#{javascript:"Nach MS Word exportieren"}]]></xp:this.value>
</xp:text>
<xp:eventHandler event="onclick" submit="true"
refreshMode="complete">
<xp:this.action>
<xp:actionGroup>
<xp_1:generateDocument documentId="wordprint"
loaded="true">
</xp_1:generateDocument>
</xp:actionGroup>
</xp:this.action>
<xp:this.script><![CDATA[XSP.allowSubmit()]]></xp:this.script>
</xp:eventHandler>
</xp:button>