datebox constraint works even when datebox is invisible

I need a conditional constraint and to achieve this I make two dateboxes making one of them invisible depending on fx.id

<!-edit->
<datebox id="editDtbx" format="dd/MM/yyyy" readonly="true" disabled="true" visible="@load(not empty fx.id)" value="@bind(fx.date)" />
<!-create new->
<datebox id="createDtbx" format="dd/MM/yyyy" readonly="true" visible="@load(empty fx.id)" constraint="no future, after ${vm.someDate}" value="@bind(fx.date)" />

The strange (buggy) behavior is the following: When the fx.id is not empty (thus only the first datebox should be displayed) I can only see the first datebox as expected but it carries with it the constraint that is given only to the second (invisible) datebox.