The IATA UN classification numbers for explosives all begin with zero., so that "23---" probably is something else. There isn't any 023x that falls into 1.1, either
HMX is UN 0226
RDX is UN 0072
PETN is UN 0150
UN0484 HMX, desensitized (HMX Dry or unphlegmatized) I think is what would be closer, but after watching the video I don't think that is what it is. Here is what I think it is.
The 6 label in the video is definitely a toxic inhalation hazard. I've never seen an X before. They are always in zones A, B, C or D. That is internationally. The label is probably a subsidiary (secondary)risk label of another primary risk. * This is rare for a munition.
The ONLY 1.1D Blasting Agent in a dry form that has a subsidiary Hazard of 6. (Toxic Inhalation Hazard) is; Dinitrophenol UN0076
Amazingly it has the same physical characteristics as those shown in the picture.
There is one other 1.1D/6 but that is a liquid and is also in the nitro family - Nitroglycerine.
Dinitrophenol is a blasting agent commonly used in "melt and pour" operations when manufacturing explosives.
Your UN0226 is for wetted with not less than 15% or more water by weight.
Your UN0072 is fro wetted with not less than 15% water by weight
You are correct about the 1.1D with a UN# beginning with 23..there ain't one I can find.