If you're stubborn about using your OLED TV in a bright room, then try to reduce the amount of sunlight hitting the screen as sunlight is detrimental to your OLED display. The heat from the direct sun will accelerate the degradation of the organic material, and the ultraviolet rays will cause tinting to the screen too.
It is extremely important to discuss the effects sunlight and especially sunlight has on your OLED TV. Sunlight will almost always cause problems for your OLED display and in many ways. OLED TVs consist of sensitive internals, and heat caused by the sunlight can damage the organic material within your OLED display.
This is because OLED TVs are extremely sensitive to heat, and usually, you’ll see somewhere that OLED TVs should not be placed over a fireplace. Additionally, ultraviolet from the sun can cause issues to your OLED display, so in the morning, it’s probably best to close the curtains because even when off, the TV can absorb heat from the sun.
The heat from the sun accelerates the degradation of the organic material within the TV. It will also push your TV to run at full brightness all the time, you’ll likely experience burn-in extremely quickly compared to an OLED display used in a friendly environment.
There is plenty of anecdotal evidence on forums explaining how sunlight has ruined their OLED TVs, and it’s likely true as the organic material within the OLED display is fragile, and complex production methods are used to protect the organic material from moisture and heat damage.