creating custom map table using tag filtering

I'm trying to create a map object that lists all errors filterd on tags. I want to add different tables to one map, where each table represents the errors for a different team.

so far I have the following

<!--Data Tables: Alarms (Small Library) Tag in HTMLbefore -->

<div class="map_object map_table" id="<@itemid>" objectid="<@objectid>" subid="<@subid>" style="overflow:auto;<#mapobject type="coordinates" subid="<@subid>" mode="<@editmode>">">
  <#mapobject type="objectgrip" mode="<@editmode>">
  <#mapobject type="htmlbefore" subid="<@subid>" var="tagfilterstring">
  <#checkobjecttype objecttype="probenode,group,device" nicemessage="true" id="<@objectid>">
  <div class="maptablecontainer" style="overflow:hidden">
    <#lang key="html.dashboard.alarms" default="Alarms" var="alarms">
    <#lang key="html.dashboard.ackalarms" default="Ack'ed Alarms" var="ackalarms">
    <#lang key="html.dashboard.warnings" default="Warnings" var="warnings">
    <#lang key="html.dashboard.unusuals" default="Unusuals" var="unusuals">
    <#objectstatus name="downsens" id="<@objectid>" show="htmllink" var="alarmcount">
    <#objectstatus name="downacksens" id="<@objectid>" show="htmllink" var="ackalarmcount">
    <#objectstatus name="warnsens" id="<@objectid>" show="htmllink" var="warningcount">
    <#objectstatus name="unusualsens" id="<@objectid>" show="htmllink" var="unusualcount">
    <#objectproperty name="name" var="objname" id="<@objectid>">
    <b><#inserthtml html="@tagfilterstring @alarmcount @alarms, @ackalarmcount @ackalarms, @warningcount @warnings, @unusualcount @unusuals (@objname @objectid)" varexpand="html"></b>
    <#table tableid="dashalarmtable"
      content="sensors"
      id="<@objectid>"
      columns="device,downtimesince,sensor"
      count="50"
      sortby="downtimesince"
      links="false"
      sortable="false"
      infoheader="false"
      filter_tags="@tag(<@tagfilterstring>)"
      filter_status="5"
      filter_status="4"
      filter_status="13"
      filter_status="14"
      filter_status="10">
  </div>
  <#mapobject type="htmlafter" subid="<@subid>">
</div>

When adding this object and adding a keyword to the BeforeHTML it seems the variable @tagfilterstring is recognized. It is listed by line 17 <#inserthtml html=@tagfilterstring.... This line shows the text from the BeforeHTML in my table.

The filtering however does not work. it only works when I add the keyword to the filter_tags line.

Kind regards Bert van Hove