X11 24plane visuals repeated many many times

If I coect via Remmina to one of my servers, and run xdpyinfo I get an output as attached file remmina - edited.txt which was edited to remove visual ids 10f through 17a to reduce the size enough that I could upload it.

This has the 24 plane TrueColour visual repeated many, many (117) times. I think I would expect to see only one instance of this.

If I coect using Hummingbird Exceed, I get only four visuals shown, one for each bit depth as shown in the attached file exceed.txt

This is confusing the heck out of an old application for which I don't have the source.

Dave