What are the issues that you are experiencing?
When using the flash, I recommend attaching it to the hot shoe and turning it on before you turn on the camera. I think the camera polls the hot shoe for devices on power up. I do not think it will always notice a device placed on the hot shoe and turned on after power up.
If there is a menu setting associated with the hot shoe that can cause the camera to interrogate the hot shoe for an added device after camera power up, then I do not know what it might be.
The 430EX III-RT is a good replacement for the 430EX II. But note that this speedlite uses Intermittent Flash Firing. To assist the camera in low light. This could be confusing and or distracting to your subjects. The speedlite can be set to use the older "Infrared/ IR" AF Assist Beam. But it only works in the creative zone ie (M, Av, Tv & P) modes. It only covers the center AF point ONLY. If another AF point is used. The IR AF Assist Beam WILL NOT be emitted by the speedlite. Intermittent Flash Firing works WITH ALL AF points.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.