Steps to Reproduce

<zk>
    <div height="500px" width="500px">
        <calendar vflex="1" hflex="1"/>
    </div>
</zk>

Click arrows to switch to the next/previous month.

Current Result

The height of the calendar will be shrunk.

Expected Result

The height of the calendar will not be shrunk.

Debug Information

It created a new div node for the animation.

Workaround

<style>
.z-calendar-anima-inner {
    height: 100%;
}
</style>