I2C Splitter Expand Module

I am new to ardupilot and am having trouble with the I2C Splitter Expand Module. I have 3 items plugged in a sonar sensor (to be used for landing), Display, and an led light. I cant get ardupiot to see any of them. I did notice in the full options a space talking about addressing but am not sure how to use that… Any help would be great!

There is issues with the I2C bus when using the splitter.
I have found that using any more than 2 devices and none of them work.
On the PH2.1 I have had to split the devices up and use 2 splitters with 2 devices on each.
Have tried getting interest from the Dev’s but they have just phoned it off.
I guess if I was the only one pointing this out then they did not take it seriously.