No 4K streaming on Netflix when Mac Mini M1 is connected to 2 displays

My M1 Mac Mini is connected to an LG 34in Ultrawide monitor via thunderbolt cable to DisplayPort which gives me 3440 x 1440 at 160hz (reflected in System Settings > Displays). Streams 4k just fine. But the moment I connect the second display (Asus 27in 2560 x 1440 at 60hz also reflected in Displays settings) via the HDMI port, streaming on Netflix caps at 1080p. I've tried lowering the refresh rate of the ultrawide, switching cables, all to no avail.

Funny thing is, I also have an M1 MacBook Air. With the lid open using the same cable and connecting to the same port on the ultrawide, I still get 3440 x 1440 at 160hz. Netflix streams 4k just fine. The resolution on my 13in MacBook Air is 2560 x 1600. So with the lid open, I'm essential driving 2 displays, but Netflix streams 4k on the ultra wide with no issues.

My M1 MacMini has 512gb storage, 16gb ram. Not using any hubs or dongles/adapters.

Thanks in advance for any replies!