Why does the audio not get recognised when I plug in the Type-C audio cable while the headphones are powered off and then turn them on?

The detection and recognition of the Type-C audio cable takes about 5 seconds. To avoid a poor experience caused by a detection failure—which would delay Bluetooth reconnection by over 8 seconds—the headphones prioritise Bluetooth reconnection first. If you want to use USB Audio, please try unplugging and plugging the Type-C audio cable again after powering on.