Replay video not playing

Hit a super sick clip but it was ruined when my replay decided to lock on to a single frame, or my character's position seemed to lock and wouldn't move when progressing the video, moving the camera, and the export is a 5 minute video of a guy not moving. 

Perhaps it could do with file size limitations, character behavior in replay, or something else.

Attached is a segment of the video which I had to trim down due to attachment file size restrictions. I am running on PC, ultrawide (32:9 with a resolution of  5120x1440p). Can provide hardware specs but they're most likely above recommended hardware.