Hello, unfortunatly i have strange audio glitches when i am using hdmi audio. I hear the music rustling the music is not hearable. I checked the boxes, and they are working right. I encounter no problems, when i am using my external usb soundcard for my headphones.
I’m experiencing the same. After upgrading to kernel 5.3.16-300.fc31.x86_64, sound through HDMI stopped working smoothly. Now there are glitches heard. In old kernel 5.3.15-300.fc31.x86_64 sound was OK!
Update to 5.4.x kernel resolved the issue for me (currently available via the testing repository).
Be aware, that when you use an nvidia driver, the new kernel might fall back to nouveu. I think everything should work as normal when the new kernel version is included in fedora.