UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:64.0) Gecko/20100101 Firefox/64.0

Steps to reproduce the problem:
Minimum Example
HTML:
<div style="display: table;">
  <span>A</span><span>B</span><span>C</span>
</div>
CSS:
span { border: 1px solid green; }
span::after { content: " "; }

The attached additional example (also available at https://jsfiddle.net/vLd9u760/) shows that this only occurs in the combination of display: table and content: " ".

What is the expected behavior?

What went wrong?
The border of "B" is incomplete and "C" is shifted below.

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 71.0.3578.98  Channel: n/a
OS Version: 10.0
Flash Version: 

Renedring in Firefox is correct.
 

Deleted: test.html 874 bytes

test.html 874 bytes View Download