This one. Seriously. It seems to a well made generic (presumably Chinese) cable sold by lots of different vendors. I just Googled 30cm HDMI cable. FWIW, I tried it with a cheap 2m cable and that worked fine too…
Remarkable similarity to this one sold by the US Holo Audio distributor, Kitsune, no? 
https://kitsunehifi.com/product/generic-i2s-hdmi-cable-0-3m/