They should include the interest rate they are using to calculate the mortgage. Based on what's provided they are assuming around a 6% mortgage which is no longer available. Tack an extra $1,000 monthly payment onto that million dollar home and an extra $40,000 to your income to make it affordable. (Assuming debt/income ratio and income taxes)
Which, having literally just bought a home, is a supremely optimistic rate to get right now. We spent $10k buying down our interest and only managed 6.9%