There is apparently also a "power problem" with the TB. That could be the reason. It's also stupid that TinkerOS doesn't have a splash screen. I would try dietpi or armbian. I personally liked them better.

The same thing happens to me, I haven't found a solution yet.

I also had this at first, then I connected another USB power supply with 2A and the monitor recognised an HDMI signal quite quickly (then just wait, I think the first boot time was longer and the screen was black).