This must be a browser bug in Chrome.

• The problem doesn't occur on Firefox or on IE.
• I have compared the page DOM before and after opening the reply widget and there are no differences, except for a few invisible elements. I tried removing those manually just in case and that also did not make the issue disappear. The page DOM of the broken and correct rendering are exactly the same.
• I stepped through the entire reply widget initialization, line by line, and this is the line that causes the problem, in ve.init.mw.Target.js: this.$element.append( surface.$element ); (this is where the visual editing surface is added). So something inside the surface must be causing this; but, removing the surface doesn't make the issue disappear, which is just crazy.

@ppelberg will discuss this with Habib

That is a web browser issue (with Chrome, Safari and Brave). Firefox and Chromium don't have this problem. I just checked with these two browsers and the display of the parentheses is correct.

In T256089#6298144, @Dyolf77_WMF wrote:

That is a web browser issue (with Chrome, Safari and Brave)...

What I experienced in Safari [i] seems to confirm what @matmarex and @Dyolf77_WMF uncovered.

For the time being, I'm going to de-prioritize this task. If/when we receive reports of this issue affecting peoples' experiences, we can revise its prioritization.

We are deprioritizing this task at this time.