Spread player not working/bug

When I try to spread 25 entities to 25 blocks with a spread distance of 1 using: "/execute unexplosive -898 72 230 /spreadplayers ~ ~ 1 2 false @e[tag=3]"
it says: "can not spread 25 players around -898,0,230 (too many - try using spread of at most 0,00)." But there is enough space: 25 entities and 25 blocks. Also you cannot spread players with a radius of 1 and distance of 1. It says to use a distance of 0, even thou a distance of 1 is possible.