Premiere not able to import DJI Matrice 4T Video

I'm not 100% sure what's going on here but DJI seems to use a unique H.265 encode sometimes and it doesn't always play nice with Premiere. And Media Encoder uses the same engine so if it doesn't work in one it won't work in the other.

I would use Shutter Encoder to transcode all of your clips to a better editing codec like ProRes 422. It's a great Swiss Army Knife of converters and you can do them in a batch like Media Encoder. And ProRes is much easier to work with than H.265/HEVC footage.