There have been intermittent issues with SPDIF output on H3 & H2+ devices.
Digging into the H2+ & H3 datasheets I encountered an important clue on
table 8.7.2.2: s_clk needs to be 4x24.576 MHz or 4x22.5782 Mhz.
Probably due to how SPDIF is a huge oversample of the audio frequency.
Co-authored-by: George Lander <lander@jagmn.com>