Buy cheap get cheap
It's normal, just return it if it's bothering you and get a new one either from the same store or another one. It's all about panel lottery, regardless of what TV you'll get.
Budget offbrand tv's will have this a lot. It's really not noticeable in 99% of watching conditions, and unless you want to spend ~5x what you spent, you're not going to escape it.
How much did you paid for that TV?
For the cheap TV's, the bulbs are on the edges. That's why you're seeing the bleeding.
Personally my next TV is going to be an OLED so I don't have to worry about bleeding again.
try changing to a different color space if possible on your device
OLED would be nice but $2000 for a 65" is out of my price range... I settled for the $450 Android TV (It doesnt really have the bleeding) - I used to have a 55" Hisense 4k and a 55" TCL Roku TV and both had this problem pretty bad but my new TV is good - guess I got lucky and won the panel lottery
My brand new LG 75in does the same even tho to a lesser extend. It's because it's a side lighting panel
Once you see it you will never unsee it .My Sony has it. My Samsung has dark patches. New TVs are terrible. I'd take my old Plasma back any day.
I couldn't get a price on this TV but especially in the low budget segment this (Backlight bleeding) is pretty common. If you can notice it when you don't have a black background I would consider a refund. If not it really depends on what you did pay for this TV if you payed more than 400$ I would give this a refund. Otherwise is this a pretty common problem with LCD backlight TVs even if your case seems a bit over the top especially for a new device, but like mentioned this really depends on what you payed, build quality plays a big factor here.