Trying to play Complex Clusterfuck on Zandronum and this happened. It involves the dynamic lights because whenever I turn them off or make them use shaders (Which makes the lights glitch out) it fixes the issue but other issues persist. Whenever firing a projectile weapon, any sprite I have seen on the map is attached to the projectile a slight distance off and sprites not attached to the projectile disappear until it hits something. Tried playing without mods and the issues persisted, even on vanilla IWADs.