
After a discussion with wildweasel about this issue, he suggested me to report it here.
In the latest dev build of Nazis!, GZDoom g2.1.pre-1859-gb5c3ced crashes on the split-second TITLEMAP gets loaded. By deleting the .ini, TITLEMAP starts working again. I used a dummy .wad to bypass the TITLEMAP and every single map (excluding TITLEMAP of course) I tried works.
CrashReport.zip and gzdoom-babycockatiel.ini (high-res texture packs are not causing the issue)