WebAcademy with Safari

When I join a WebAcademy session on my mac/iPad/iPhone with safari, I have no audio. When I use chrome on my Mac, there are no problems with audio. I already tried to delete all cookies/data related to the session url in safari but without success. Haven't found any settings related to audio access rights in safari which I could switch.
Am I the only one with missing audio in safari?

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