Coherence image is noisy and wavy

I have created 12 days coherence images for nov08_nov20 and nov20_dec02 2024 over Punjab, India. While the first coherence output looks fine, the nov20_dec02 image looks good on top part and noisy and wavy on bottom.I tried both with snap desktop and snappy. but still same output. I used all same properties for both images I couldn’t figure whats wrong. Could anyone help please?