'Live' Section Question

[HumbleChief]

I've been moving to more and more 'live' elevations and sections as my models become more accurate and wonder how live sections update and why. I have a live section that I've heavily annotated and just realized the floor is raised on a stem wall with a small crawl space instead of the monoslab I currently have modeled.

I've saved the floor plan so I can experiment because i don't want to lose the annotations in case I make too many errors in switching the foundation.

Here's my question. I have both the floor plan and section views open and when I delete the foundation level nothing changes in the section view. The original foundation still shows up as an unchanged mono slab. So is this section not as 'live' as I think it is? The framing has updated to TJI's that replaced the 2 x 10's originally modeled so it seems to act 'live' but the foundation remains unchanged even when I delete the entire floor.

I think this is pretty easy but am stumped at the moment.

Thanks for any help.