Since it's all new(ish) gear you have a warranty issue. If they can't resolve it then you return the defective gear for something else.
HDMI ARC can be so bad that most of us write "what a mess" and give the nod to the usual RECEIVER SYSTEMS.
That said did you try all the usual setups? That is the player to the TV on a NON-ARC port and then the ARC port to the bar? Do you have the other option of optical to the bar?
I connected my Sony blue ray player TO MI TV hdmi port AND connected my Yamaha soundbar USING BOTH ARC PORT IN TV AND SOUND BAR, but no audio even enabling audio to hdmi arc.
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