This style will cause me a bug

[951565664]

<div class="rc-collapse-content rc-collapse-content-active" style="height: 38px;"> 

This bug cannot be reproduced steadily. When a bug occurs, style has a height.When normal, style has no value and I found the style will change

I read the source code and ensure that the latest version is installed, but I don't know where to add this style， I also read animate，I can't when to change style