Opt 状态 YSC18902*****

5.3 号  case was received然后自己发现一个东西填错了，然后写了一封信到uscis
5.31 状态变成
Correspondence Was Received And USCIS Is Reviewing It,然后就在一直是这个状态，但是日期更新了
一开始是
On Mar 31, 2018, we received your correspondence for Form I-765,
然后变成
On June 4, 2018, we received your correspondence for Form I-765,
今天变成
On June 15, 2018, we received your correspondence for Form I-765,
我只交了一份材料，为什么这个状态的日期会不断更新呢？是他们收到别的更新材料的意思吗？

谢谢大家！