AF expand surround -7D2

Hi, this may seem like a stupid question so apologies. I like to use AF expand surround as the autofocus on my 7D mkii. What I've notice is that if I take the image using one shot then when the AF locks on several AF points are active. When I take the image in ai servo, then this doesn't happen and it's always just the center point. Can anyone explain why this is please?

Just seems a little odd and maybe I have a setting wrong.

thanks

simon

In AI-servo, the expansion points that were used in acquiring focus are not highlighted in the finder.

Ah! Thanks Arash