UserAgent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36

Steps to reproduce the problem:
1. first open a web
2. click the input frame
3. input frame has no cursor
4. refresh the tab,it can be normal
5. it appear or arrive by chance 

What is the expected behavior?
can regular service input

What went wrong?
input frame can not use appear or arrive by chance

my html frame is:

<div class="username">
<input type="text" class=""><i></i>
<button tabindex="-1"><i></i></button>
</div>

.username{position: relative;}
.username>input{position:absolute;left:0;top:50%;width:10px;height:10px;}
.username>button{position:absolute;right:0;top:50%;width:10px;height:10px;}

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 57.0.2987.133  Channel: n/a
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: