Feedly is suddenly broken (not displaying RSS feeds)

[JonathanReeve]

Version info:

qutebrowser v2.5.0
Git commit:
Backend: QtWebEngine 5.15.8, based on Chromium 87.0.4280.144
Qt: 5.15.3

Does the bug happen if you start with --temp-basedir?:
Yes.

Description
RSS feeds on Feedly (feedly.com) have stopped displaying. This problem only seems to occur on Qutebrowser.

How to reproduce

• Go to feedly.com, and load an RSS feed like this one
• Notice that the feed doesn't display—it's just blank.

I've attached a screenshot of the issue, along with the web inspector panel open, just in case any of those errors are relevant.

[The-Compiler]

It works fine on the qt6-v2 branch (see #7202) with a newer QtWebEngine. I've tried to debug this a few days ago, but unfortunately got nowhere, so I'm afraid there isn't much we can do until that's in.