@monika
As a temporary fix you could make a copy of “members-header.php” in your child theme and rename it to “original-members-header.php” then in the one named “members-header.php” you can delete lines 35-43 like in the below code and save it. If it causes issues just delete the members-header.php you modified and rename the one you copied “original-members-header.php” back to “members-header.php”
<?php if ( bp_is_active( 'activity' ) ) : ?>
<div id="latest-update">
<?php bp_activity_latest_update( bp_displayed_user_id() ); ?>
</div>
<?php endif; ?>
