Is this with a binding or with the “HA Plugin”?
I’m using the HA plugin from this thread to control on/off/brightness, and reading from the Matter device in Home Assistant when listening for button press events. I’ve heard of the term “Matter bindings” but I don’t think that’s what I’m using. All I did was connect the switch to my Home Assistant normally by scanning the QR code.
If you would like to Message me with a copy of the automation(s) you are using in HA and also a screen shot of the device configuration in HA I will take a quick look at and see if I see anything obvious.
I tried what I believe to be your configuration with a VTM30 as the switch using a VTM31 (white dimmer) as the target. I get near instantaneous response and the dimming using the plugin appears to be quite responsive.
How many smart bulbs do you have?
Andrew