存款买房有利率问题结果错误

不知道为什么我运行的结果跟预期输出不一样，哪里出问题了？
问题

我的代码

total_cost = float(input())         # total_cost为当前房价
annual_salary = float(input())        # 年薪
portion_saved = float(input()) / 100  # 月存款比例，输入30转为30%
semi_annual_rise = float(input()) /100     # 输入每半年加薪比例，输入7转化为7%

portion_down_payment = 0.3      # 首付比例，浮点数
down_payment = portion_down_payment * total_cost   # 首付款
print('首付',down_payment)
month_salary=annual_salary/12
current_saving = 0                                # 存款金额，从0开始
number_of_months = 0

rate=0.0225/12
month=0
while current_saving<down_payment:
    month+=1
    current_saving=current_saving*(1+rate)+month_salary*portion_saved
    if month%6==0:
        month_salary=month_salary*(1+semi_annual_rise)
    if month%12==0:
        print("第{}个月月末有{:,.0f}元存款".format(month, current_saving))
print("需要{}个月可以存够首付".format(month))


![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/555242873566157.png "#left")

预期与实际输出

total_cost = float(input())  # total_cost为当前房价
annual_salary = float(input())  # 年薪
portion_saved = float(input()) / 100  # 月存款比例，输入30转为30%
semi_annual_rise = float(input()) / 100  # 输入每半年加薪比例，输入7转化为7%

portion_down_payment = 0.3  # 首付比例，浮点数
down_payment = portion_down_payment * total_cost  # 首付款
print('首付', down_payment)
month_salary = annual_salary / 12
current_saving = 0  # 存款金额，从0开始
number_of_months = 0

rate = 0.0225 / 12
month = 0
while current_saving < down_payment:
    month += 1
    #current_saving = current_saving * (1 + rate) + month_salary * portion_saved
    if month % 6 == 0:
        month_salary = month_salary * (1 + semi_annual_rise)
    current_saving = current_saving * (1 + rate) + month_salary * portion_saved  #计算加薪后的工资要放在这里
    if month % 12 == 0:
        print("第{}个月月末有{:,.0f}元存款".format(month, current_saving))
print("需要{}个月可以存够首付".format(month))

问题出现在第六个月的时候涨薪了，计算这个月的工资应该按照涨薪后的算，更改后的代码：

total_cost = float(input())  # total_cost为当前房价
annual_salary = float(input())  # 年薪
portion_saved = float(input()) / 100  # 月存款比例，输入30转为30%
semi_annual_rise = float(input()) / 100  # 输入每半年加薪比例，输入7转化为7%

portion_down_payment = 0.3  # 首付比例，浮点数
down_payment = portion_down_payment * total_cost  # 首付款
print('首付', down_payment)
month_salary = annual_salary / 12
current_saving = 0  # 存款金额，从0开始

rate = 0.0225 / 12
month = 0
while current_saving < down_payment:
    month += 1
    if month % 6 == 0:
        month_salary = month_salary * (1 + semi_annual_rise)
    current_saving = current_saving * (1 + rate) + month_salary * portion_saved
    if month % 12 == 0:
        print("第{}个月月末有{:,.0f}元存款".format(month, current_saving))
print("需要{}个月可以存够首付".format(month))