Hi!
I had the same issue. It seems with the most recent CM5, especially the 16gb, the tips in below will fix it. After that you can also apply the patch that the topic is about.
And for the image, start with one of the images by REX that you can find here on the forum. Bookworm or Trixie. This one for instance: Trixie 6.12.y for the uConsole and DevTerm - #154 by Rex