On several RockPro64 boards I experience infrequent freezes, mostly directly on boot, but also after some longer (hours, days) uptime. I use the official power adapter and no additional hardware except a PCIe adapter for an SSD, which works flawlessly when operational.
When looking at the kern.log, there are quite a few errors and warnings, but comparing to a successful boot these are all also present. So I don't think they cause the freeze directly.
Currently, I recorded