I came across this bug just a minute ago (desktop). When in the editing window, if you italicize or bold a bracketed link, it will a) be clickable in the preview window and b) will not open a new tab.
If the link is not formatted, it will not be clickable.
Steps to Reproduce
Go to your forum preferences > interface > other. Make sure “Open all external links in a new tab” is checked.
Open the editing window (reply, PM, topic, etc)
- Click on the outcome in the preview window
Hope this helps!