Serious OpenFL 4.x rendering problem on iPhone 6 Plus?

Recently, I am updating my openfl project to 4.x. But rendered graphic is smaller than before on iPhone 6 Plus and stays in the lower-left corner of the screen. I tried the PiratePig from the openfl-samples and got the same result.

But there is no problem when the games were running on iOS simulators.

Please click the image to view its actual size.

Did anyone encounter the same problem?

Does it behave differently if you add <window allow-high-dpi="false" /> to the project.xml?

After adding <window allow-high-dpi="false" /> to the project.xml, the scale is correct now.
But the graphics quality of images and texts decreases a lot. :confused:

It is worth mentioning that the touch position is also incorrect for allow-high-dpi=“true”. It feels like the interactive elements are still in their original positions and only drawn on wrong positions and scales.

I have submit a bug on github and would like to try to fix it myself. Which part of code should I examine to find the root causes? @singmajesty