Logging on for the first time to the PS5 client, i was surprised that the opening brand videos had no audio. I thought it might be an audio setting, but when they were over, the initial screens for logging on appeared and the audio returned. So I clicked through to get to the character choice lobby. The opening cinematic started and audio disappeared. Once ot was done and I entered the lobby, sound came back and remained for the rest of that session.

Today, however, the initial brand videos again had no sound. I didn't test the cinematic, though.