Wed Jan 19, 2022 9:37 am
I spoke with support and they suggested it was an HDCP issue on Mac since it appeared for a few seconds before disappearing. I also read some forum threads / reddit posts suggesting it could be a frequency problem, HDCP, or the chipset on the adapter I used. I had actually used a few cables, including a DisplayPort to HDMI adapter and they all produced the same results.
I suspected that a chipset issue made sense, and was also the cheapest way to solve the problem without a total rework of my plans. I bought a new cheap USB-C to HDMI adapter and this one works flawlessly. I can't post links but if you look on amazon.ae you will find something with the title "USB C to HDMI Cable 3FT, CableCreation USB Type C to 4K HDMI Cable Adapter for Home Office, for MacBook Pro/iPad Pro 2020 2019, Surface Book 2, Dell Xps 15, Samsung S10, S9 Plus, 0.9M, Black"
Based on this I think it was an incompatibility issue on chipset used by the adapter.