My Asus Tuf A15 Keeps Freezing While Streaming Videos—What Can I Do?

I'm having a really frustrating issue with my Asus Tuf A15 laptop; it completely locks up whenever I'm watching videos online, especially on YouTube. The only way to get it back is to force shut it down by holding the power button. I've tried just about everything I can think of—with no success! I've had a tech guy look at it, and he couldn't find the problem either. I've cleaned the laptop, reinstalled Windows along with all the drivers and BIOS updates, swapped the SSD slot, and even changed the Wi-Fi card. Unfortunately, I can't send it for repairs since I bought it on Amazon and it's way past the 30-day return window, plus it's out of ASUS warranty. Any advice on what I can do?