Ah! That makes sense, so to try and correct that I did the following:
Select all wall types on Floor 1 and uncheck "foundation" walls box
Click Okay
Select Build > Floor > Build Foundation and check "Automatically Rebuild Foundation"
Click Okay
Goto Floor Zero and check results --- nothing there?
Change the Room Type from Slab to another type, click Okay
Goto Floor Zero and check results -- Success!
Change the Room Type back to Slab, click Okay
Still success!
Not sure why I had to do steps 6-9 but it's fixed now!
Kudos to you, David for taking the time to look into this for me!
All the Best!