Mark pieces on map as moved

My module has got the “Mark all pieces on this map as not moved” command. When I get the vlog of another player, before stepping forward through the log file, it is sometimes useful to mark all pieces as not moved in order to see at the end of the vlog which units have been moved on the map.
When I do this, sometimes (I could not find a way to understand why it happens only to some units), moved units are not recognised as moved and the “moved” mark does not appear close to the unit counter.
If I do not mark all pieces as not moved before stepping forward through the log file, this does not happens (in this case I can check it only for units that weren’t already marked), that is every time a unit is moved the mark “moved” appears correctly.
Can you help me to understand why? Is there a setting I forgot to check?

Thanks.

When you load a vlog, the module loads the game state and goes from there. The pieces’ moved status is part of that state. Vassal is not prepared for your state changes while it’s replaying the log. It would be like while sitting in a theater watching a play, you stood up and threw a stink bomb on stage. Chaos would ensue, and the show would not go on. Marking all as unmoved while the vlog is replaying is you throwing a stink bomb into Vassal.

I suggest you and your opponent mark all as unmoved at the start of your turns as a courteous routine. Avoid screwing around with pieces during a replay, or there will be hell to pay.