I have a MacBook Air , 2 external monitors no signal to one of the monitors

If your MacBook Air is from 2017 or before, or is one of the new M1 MacBook Airs, it only supports a single external display. Only the 2018, 2019 and 2020 Intel MacBook Air models support two external displays.

I have an M1 Macbook Air. Connecting both into the USB-C drives and only one works. But what is weird is the other one is putting out sound when on Zoom calls. I have the LG 4K screens that I bought for my 2018 Macbook Pro and they worked great. Now I went over the M1 Air and only one works. I have done all the trouble shooting if I plug one in it works on the A screen, if I plug another one in it works on the B screen but not A. Tried detect displays, rebooting, plugging in and out and nothing works.

When both are plugged in only one works.

That's what is supposed to happen. The M1 Mac notebooks (Air and Pro) support only one external display – resolution up to 6K, but only one.

Simultaneously supports full native resolution on the built-in display at millions of colors and:

• One external display with up to 6K resolution at 60Hz

From MacBook Air - Technical Specifications - Apple.