If your video has audio, try using the "multicam" process instead of merged clips. In general, there are fewer problems with multicam editing versus merged clips. Including that say for "top & tail" editing using the Q and W keys, that are not available for merged clips.
Q ... cuts the clip from the CTI to the beginning of the clip on the sequence, does a ripple to close the gap.
W ... cuts from the CTI to the end of the clip, and again, does a ripple to close the gap.
Very useful editing tools, NOT available in merged clips processes.