I noticed something very weird in the latest GZDoom beta. When i loaded the DuduKrazy's Guns 4 mod, i noticed that the numbers (all PNG files) and a few other graphics (PNG, too) didn't show up at all. It doesn't happen with an older version (GZDoom 1.3.8 beta).
The screenshots below are from the DuduKrazy's Guns 4 mod, but i believe this can also happen with any mod that uses png images as graphics in the SBARINFO lump. (i'm not sure, though)
1.3.8 beta (older version) and 1.3.11 beta (latest version) respectively.