Phoenix liveview checkboxes are not updated (the UI)

Hi all,

in a live component I render some checkboxes and a button to check all of them:

...
<%= for x <- @list_of_things do %>
      <input type="checkbox"
        id=...
        name=...
        phx-click="some-event"
        phx-value-column={elem(x, 1)}
        phx-target={@myself}
        checked={is_checked?(x, @another_list)}
      />
<% end %>
<button type="button" phx-click={JS.push("check-all", target: @myself)}>
...

Inside the event handler I update @another_list
{:noreply, assign(socket, another_list: [...])}

the is_checked? function gets called (I inspected inside it) and it is returning true a number of times equal to the number of checkboxes.

Anyway, the UI doesn’t show all the checkboxes as checked until I refresh the page.

What am I doing wrong here?

Cheers!