Sequencer Issue- Not rendering asset's material

So I’ve got this sequence which I’ve rendered in UE4 V4.21 but as one can observe in the attached photo the trees aren’t rendering properly. I’m rendering through the sequencer in 1080p at 24fps. The trees are a free asset from the Infinity Blade Grass Lands pack available in the UE4 marketplace, and are grouped together into one single asset. I’m not entirely sure why this is happening, so any help or ideas would be appreciated! Thanks in advance