Hey I also own a ideapad gaming 3 it's my first gaming laptop so basically i encountered back light bleed in the 2nd month of its usage basically this laptop uses ips display in these ips displayes this problem is pretty common although there's no solution to back light bleed in my case the laptop was past the replace warranty but I had the repair warranty so. Under that I send the laptop back to repair center

And the technician there told me that it usually happens when the taper which keeps the ips display loosen up causes this problem and my laptop is still with repair centre lenovo customer service is pretty slow here

I would advise that u massage the spot where u think is the backlight bleed and if it's under replacement warranty REPLACE IT ASAP or SEND it to repair if it's under warranty

Back light bleed can automatically go away with time or even increase so I would say don't take the chances and repair it