I tried to install using instructions from Rock64 website. Concatinated the image, and partition files as instructed. Flashed an SD card installation started until I reached the place where a kernal was to be downloaded and it errored out saying no kernal modules were found? I selected several mirror sites with out success. Not impressed so far.
Maybe you can share more details on what you download from where, which image you use and what exactly the issue is. Just with the information given, nobody would be able to assist.