• Version? 41.78 and probably most 41.xx versions
• Singleplayer/Multiplayer? Yes
• Host or dedicated? Yes
• Mods? No
• Old or new save? Yes
• Reproduction steps:
Hit as many zombies as you like with a vehicle, blood intensity on the front or rear will never exceed 3.999%
Blood intensity seems to be capped at 4% give or take a rounding error. If you force it to 5% it will then work until around 25% where it will get stuck again. Manually setting it 1% higher every time it gets stuck will allow it to proceed again, but it will get stuck every couple percent points up until around 60%, after that it functions properly all the way up to 100%. My best guess is floating point issues, as blood intensity is cast a bunch of times between float and byte, but I can't verify that. I can verify that this happens to other players as well, however.