When you disable local control, you are saying that I don’t want the switch to PHYSICALLY control anything. So it makes sense the LED bar won’t move as the switch isn’t controlling anything. It’s just a scene controller. If you want the LED to work, then use Smart Bulb Mode and associations.
I don’t use associations, but I believe @Chris and/or @kelchm have the associations and LED dimmer working and syncing for a 3-way. @Chris describes what he did here: