I had the same issue. I fixed it by trying the troubleshoot from Pro Tools Expert here: https://www.pro-tools-expert.com/production-expert-1/how-to-listen-to-dolby-atmos-without-costly-hardware
I ended up using the Blackhole 16ch virtual audio bridge: https://existential.audio/blackhole/
If blackhole doesn't work, try other methods listed in the Pro Tools Expert article.
Hope this helps
Trolomite
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