After changing my key binds back to the previous vehicle controls. Spacebar to exit and E for secondary. It is not possible to exit a skimmer if spacebar is set to the exit vehicle key bind as it seems like the jumping action takes priority. This occurs irrespective of the player jump key bind and the issue does not occur for sparrows. The exit key bind does however work if the player on the vehicle is airborne, at which it is not possible to jump and hence exiting is possible. This can be seen in the video link.