Filter panel: setting a field value via some function

I placed the following code in ModifyMenyItem event (note I have a field begd in my Acties table that contains the entrydate of the action):

// Place event code here.
$tody = date("d-m-Y");
$filter = "f=(begd~equals~" . $today . ")";
if($menuItem->getLinkType() == 'Internal')
{
if ($menuItem->getTable() == 'Acties')
{
$menuItem->setParams($filter);
}
}
// Use "Add Action" button to add code snippets.
return true;

I checked using the echo command that the params are correctly set but nevertheless in the url in my browser I only see the Acties_list.php and not the added params.

I can see that there is a variable that is misspelled, $today vs $tody. Not sure if this matters.

In the actual code the $tody variable is written as $today (I made some error while pasting the code).

Today I saw that my coding worked OK when I click on Acties in the menu I created in Style/MenuEditor.

When I click on Acties in the menu I created in Designer/CommonPages/Menu I can see (using the echo command) that the Params are correctly updated but nevertheless the resulting url still shows the old params. I guess this is a bug (?).

Just to be sure my actual code in the ModifyMenuItem event (which apparently is executed in BOTH cases!) is:

// echo $menuItem->getTable();
// echo $menuItem->getParams() . "oud";
$menuItem->setParams($filter);
// echo $menuItem->getParams() . "nieuw";
}
}