Watching demos doesn't seem to work right

I'm trying to watch 4shockblast's NM Speed demos of Sunder map 10 and 13, which I downloaded from DSDA (attached below). He uses Prboom+ so my command is

prboom-plus -iwad DOOM2.WAD -file sunder/Sunder\ 2407.wad -playdemo demos/downloaded/su13n346.lmp

and something similar for the map 10 run. Everything works fine until I watch the demo: instead of a final successful run, I'm seeing him die a bunch of times and ultimately not getting anywhere. The movement through the map seems normal up to death so I don't think the demos are desyncing. What am I doing wrong here? Is there a separate WAD for old Sunder that I should be using?

su10n751.zip

su13n346.zip

Try the file named sunder.wad in this version, which you can get by clicking the Sunder header at the top of the DSDA page for Sunder. This is the version that we run old Sunder on because modern Sunder isn't finalized and could see changes to the maps that would affect demo syncing, and based on what your issue is, likely already has.

45 minutes ago, Maribo said:

Try the file named sunder.wad in this version, which you can get by clicking the Sunder header at the top of the DSDA page for Sunder. This is the version that we run old Sunder on because modern Sunder isn't finalized and could see changes to the maps that would affect demo syncing, and based on what your issue is, likely already has.

It works, thanks. These are some great demos.