Areas with no sky light are incredibly dark when using the "High Contrast" resource pack

Here's a video

 

What is the issue?

The end becomes near pitch black and borderline unplayable

 

How to replicate it?

Simply activate the "High Contrast" resource pack or turn on the high contrast feature and enter the end

 

Extra remarks:

• Lighting seems to affect the severity of the darkness
• Night vision seems to have no effect
• The End Islands are also affected