Start server as Vanilla 1.8.8. /give PlayerName skull 1 3
{SkullOwner:PlayerName}Head is spawned with proper skin.
Change server to spigot 1.8.8, use the same map. Issue the same command and the player head is spawned in with Steve's skin.
Change back to Vanilla 1.8.8, restart the server (same map) and try the command again. The proper skin is on the given player head.