UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Example URL:
https://codepen.io/anon/pen/vrwRvW

Steps to reproduce the problem:
https://codepen.io/anon/pen/vrwRvW

<div class="container" style="display: grid; grid-auto-rows: auto;">
    <div style="grid-row-end: span 995">1 - 995</div>
    <div style="grid-row-end: span 1">996</div>
    <div style="grid-row-end: span 1">997</div>
    <div style="grid-row-end: span 1">998</div>
    <div style="grid-row-end: span 1">999</div>
    <div style="grid-row-end: span 1">1000</div>
    <div style="grid-row-end: span 1">1001</div>
    <div style="grid-row-end: span 1">1002</div>
    <div style="grid-row-end: span 1">1003</div>
    <div style="grid-row-end: span 1">1004</div>
    <div style="grid-row-end: span 1">1005</div>
</div>

What is the expected behavior?
Rows above 1001 should also be displayed correctly.

What went wrong?
More than 1000 spanned rows lead to a display error.

Does it occur on multiple sites: N/A

Is it a problem with a plugin? No 

Did this work before? No 

Does this work in other browsers? Yes

Chrome version: 67.0.3396.99  Channel: stable
OS Version: OS X 10.10.5
Flash Version: