Hello again.
I recall having problems with my Aura shortly after I got it and put a post on the forum; replies suggested my signal strength could be too high, causing distortion and loss of digital data. See this post :- https://myhumax.org/forum/topic/pixelation-and-dropouts-on-playback
Could be you actually need an attenuator to get optimum signal strength and quality. The Aura seems much more sensitive to signal strength, the contributor suggested an optimum level of around 90% if I remember correctly.