Screen dullness in Tab S8

[Rakibul07]

I have been using tab S8 for 2 years. But A month ago I have noticed a dull area in the bottom left corner as you can see from the picture. For the past month it's radius increased a little bit but negligible. I don't notice it in pure black screen. And I think touch works completely fine in there. Is that a conern? or should I just sleep on it? Any suggestions what it might be and how I can prevent further damage?

This is from previous month 

This is from today

[cs_member10]

Dear Samsung Member,

Greetings from Samsung Customer Support!

As per your concern, we would request you kindly visit the service centre and inspect your device with the technical team end, they will provide you with all the information in a better way after inspecting the device physically.

You can locate your nearest service centre with this given link: https://www.samsung.com/in/support/service-center/

Warm Regards,
Samsung Customer Support