The headphones may have been connected to the computer through Low Energy (LE) communication mode. This usualy occurs when the headphones are paired without pressing the Power button for seven seconds, and may result  in the headphones not pairing to the computer or the computer not having sound.

To resolve the issue, make sure to press the Power button on the headphones for seven seconds to put the headphones in pairing mode before you pair the headphones with the computer.

After the headphones are in pairing mode, both WH-1000XM4 and LE_WH-1000XM4 appear on the computer screen. LE_WH-1000XM4 may appear first, and then a few seconds later WH-1000XM4 will appear. Wait for the WH-1000XM4 to appear on the computer screen and select it.