Blurry text in unselected input field on wayland with fractional scaling

[fritzrehde]

Version info:

qutebrowser v2.5.4
Git commit:
Backend: QtWebEngine 5.15.14, based on Chromium 87.0.4280.144
Qt: 5.15.9 (compiled 5.15.8)

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

Description
I have attached a screenshot that demonstrates the issue. When using a fractional scaling setting on wayland (sway) of 120%, I get blurry text when I unselect a text box (e.g. when writing this exact issue). This is not the case for other browsers I have tested (e.g. firefox). This only happens when I write a certain amount of lines in the textbox, I think I have to write so many lines that the textbox window gets expanded vertically.
Blurry text: when input field is not currently selected/focused.

Non-blurry test when input is currently selected (in input mode in qutebrowser).

How to reproduce

Use a wayland compositor (wlr-roots based ideally, so not Gnome or KDE with wayland enabled, but sway, hyprland, river etc) with fractional scaling enabled to 1.2/120%. Go to github.com/qutebrowser/qutebrowseer/issues and try filing a new issue. Write a lot of text into the main text box containing the issue's content, write so much that you will have to scroll slightly down to see everything on screen. Then, click off of the textbox, and you will see that the text goes blurry. Once you click on the textbox again, it will become non-blurry again, until you click off of it again.

[The-Compiler]

I doubt this is a qutebrowser-specific issue.

Could you please try:

• Another browser using QtWebEngine 5, e.g. KDE Falkon
• qutebrowser with Qt 6: Switching to Qt 6 by default #7202

[The-Compiler]

@fritzrehde Any updates?

[The-Compiler]

Closing due to inactivity.