That's how it was supposed to work. But if you had a negative balance, it wasn't doing that.  It subtracted the cost of the change from your current treasury balance (which made a larger negative balance), made that the amount of the lease, and then set your treasury balance to zero.  Which essentially just meant that you'd be paying 10 bc per month for longer than you would if you had started with a zero balance.  If you were making a change where the cost was actually zero, you sould still get a lease because it would convert your debt to the lease.

So now it checks to see if your balance is positive before it subtracts the cost of the lease, so that it only creates the lease for the debt created by the change rather than rolling in your debt as well.

It might be an interesting feature in the future to let you get a loan to get rid of your debt, but that's not the intention of Xeno Ethics.