SSRS - Rows are repeating in table

I am creating a report in SSRS and i am having an issue that the table is repeating. In the table 6 records should be presented but insted are shown 12. Repeating rows on the left and only one row on the right On the left side is the table with repeated rows. And this is how it looks like in designer (left table) Designer

I found this link SSRS - Why is my table duplicating rows? where the answer is that the Details group that gets set up by default should be deleted. I deleted the Details group and after that i just added a fields Table without details group (right table)

The Issue that i have now is that the duplicates are not shown, but only one record appears, no more lists. In the link above it states that aggregation needs to be set up. Where and how do I do it? Also, if there are any other solutions, I would appreciate any suggestions. And for the Info i only have one DataSet. I am using fetchxml in query to get the records from dynamics 365. In that fetchxml i have two link entities (contacts and related child accounts). It seems that as soon as two linked entities are in one fetchxml and the attributes are available of the child entities it starts to repeat the rows.

So i found the solution for this issue. I started to create different datasets for the child records so that only one child table is available in fetchxml. For example:

<?xml version="1.0"?>
<fetch distinct="true" mapping="logical" output-format="xml-platform" version="1.0">
<entity name="account">
    <attribute name="name" />
    <attribute name="accountid" />
    <order descending="false" attribute="name" />
    <filter type="and">
        <condition attribute="accountid" value="@AccountId" operator="eq"/>
    </filter>
    <link-entity name="connection" from="record1id" to="accountid" link-type="outer" alias="connections">
        <attribute name="record2roleid" />
      <link-entity name="contact" from="contactid" to="record2id" link-type="outer" alias="contacts">
        <attribute name="firstname" />
        <attribute name="lastname" />
        <attribute name="telephone1" />
        <attribute name="emailaddress1" />
      </link-entity>
      <link-entity name="connectionrole" from="connectionroleid" to="record2roleid" link-type="outer" alias="role">
        <attribute name="name" />
      </link-entity>
    </link-entity>
  </entity>
</fetch>

This xml actually has only one linked entity starting from the "connection". If i put further linked entities like this

<link-entity name="connection" ... >
....  
</link-entity>
<link-entity name="someEntity" ... >
    <attribute name="someEntityField" />
</link-entity>

than the rows are staring to repeat in tablix. So just create another dataset with another child entity and use the fields in tablix.