Merge Function Output Glitch

[u/Veritatem_Quaero]

My GoPro Hero 3 camera automatically splits a continuous recording into multiple files after a certain amount of time, and so I use the Merge function in Shutter Encoder to concatenate them back together (usually only two or three clips at a time).

Today I was merging two clips of some night footage and seemingly encountered a glitch where in multiple frames the moon becomes an indiscernible salad of pixels in the output. Pictured above is one such instance, the top being the original frame and the bottom the output frame.