Pixelation is a symptom
It can come from weak signal, noisy signal, bad cable, water ingress, splitters or wall plates.
Weather can reveal faults
Water inside cable or connections may make reception worse during rain or humidity.
Amplifiers are not always the answer
Amplifying a poor signal can amplify noise too. Testing comes first.
Multiple outlets need balance
Every splitter and cable run changes the signal level.
Need site-specific advice?
Photos, a rough floor plan, existing equipment details and a short explanation of the issue are usually enough to begin a practical discussion.