Okay I tested a little more using official modules again and perhaps it's bloodclaw causing the problem...
• lv20 Warblade, upon entering multiplayer game, I was asked to re-select all maneuvers. It appears all maneuvers are available. Thus, not a problem.
• lv21 Warblade, lv5 Bloodclaw, upon entering multiplayer game, I was asked to re-select and only very few maneuvers are available.
• lv21 Warblade, lv5 Bloodclaw, upon entering single player game, no problem.