FAQ: Why Do the Proceeds From Selling a Home Show Up as an Expense in Projections?
It could be that the platform will calculate an additional "expense" in the year of sale if you add sale costs in the Foundation > Selling A Home section. For example a 5% sale cost on a $1M home will add $50,000 in transaction fees as an expense in the year of sale.
If also might be that the platform includes a "Saving & Investment" contribution in the year of sale, this is the platform investing the proceeds of the home sale. IF the platform doesn't have any where to put the proceeds (for example, if there isn't a non-registered account enabled and if TFSA contribution room is maximized) then the platform will calculate a "surplus" that goes into a general "cash account". This isn't ideal and should be rectified by enabling a non-reg account in your Profile.