签证check过开学日期，大使馆要求更改sevis program start date才能出签

今年8月4号在温哥华大使馆面签，但是被check了。学校是9月9号开学，然而9月8号大使馆才发邮件说，我需要联系学校在SEVIS系统更新program start date。邮件内容如下：

Dear Mr. XXXX,

The administrative processing on your case is now complete, before we can proceed further you need to take the following action:

You need to contact your school – Northeastern University and have them update the SEVIS program start date to a date into the future (at least 20 business days from now or later). Your current SEVIS program start date is valid until 09 September 2020 and we cannot proceed with the visa issuance until that date is updated. SEVIS # XXXXXXXXXXX.

Please advise this office as soon the SEVIS program start date is updated. Please note that the administrative processing is only valid until (02-JAN-2021]. This means we must complete the visa process prior to [02-JAN-2021] otherwise the administrative processing expires and the file will be closed.

Thank you for your prompt attention to this matter.

联系学校以后，学校可能没明白意思给我开了最晚10月2号报到的Late Arrival Letter，转给大使馆说不行，必须要在SEVIS里面改项目开始日期，一经更改他们看到立刻可以出签。

请问一下，学校一般可以随便给我在SEVIS更改program start date吗，比如往后改20天那么我秋季还能入境上学。
还是不能这样改只能改到明年春季，而我现在又已经开始上课了。
有没有类似情况各位可以分享一下经验吗