UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36

Steps to reproduce the problem:
1. Visit https://www.scirra.com/labs/bugs/download.html
2. Click the link

What is the expected behavior?
A download should be started without attempting to open a new browser tab.

What went wrong?
The page specifies <base target="_blank">. The presence of this tag causes a new tab to be opened briefly, which is then immediately closed and the download starts. This causes the page to flicker (the page is black so you can see the white flicker more clearly), the address bar to briefly show the blob URL, and sometimes a new tab can be seen animating in before disappearing.

This is merely an annoying flicker, unless you have a browser extension which intercepts requests or new windows. For example installing UBlock now causes the download to be blocked.

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 65.0.3325.181  Channel: stable
OS Version: 10.0
Flash Version: 

This affects our PWA Construct 3 (editor.construct.net).

We only recently got reports of this, so it could be a regression in Chrome 65.