Hi I’m running 64 bit Raspberry pi OS on a Raspberry pi 4 - 8 gb in an Argon One M.2. I’m having problems with HDMI output. The Pi will start, I can see the boot screen, then a black screen. I know Ras pi OS 65 bit is working as I pulled out the PI and just used the micro-HDMI. I also get a very small screen if I use VNC. By a process of trying different screens, and cables it seems to the Argon case that is throwing it off, I have two Argon case, one is running 32 bit Raspberry pi OS on a Raspberry pi 4 - 4 gb with no problems. Any ideas.
What it sounds like is that you don’t have enough power to drive the M2’s video circuitry. Just a long shot, but it mirrors the symptoms I found with my Pi Zero2 in a POD. See this thread Argon calls for at least a 3 A power supply for any Pi Zero model in the POD, and that’s also the spec for a Pi4.