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Some users had similar issues after Stable Update 2022-12-06 with kernel v5.15.81:
Audio randomly cutting out on Manjaro KDE
Audio only works the first time I play something. Then I have to restart to get it working again
But there is now another update 2022-12-20 including kernel v5.15.84
If audio is not working as expected with the updated kernel, try installing kernel v6.0