Okay, so I encountered this bug in a pvp match. What happened was after an enemy placed a trap down he fled the fight a few turns later. Though the trap's icon and placement on the map disappeared, the trap's effect itself did not, which I later learned the hard way. Having forgotten about the trap, I moved martin valvida to the space where it was at before, and naturally he got hurt by it, and eventually this is what caused his downfall by the enemy bonnie anne's own hands (or gun rather-you get the idea).
Me and some friends were able to reproduce this bug (and yes it is a bug). To reproduce it, you first need the following.
1. A minimum of 3 people (2 people on one team (trap person+someone else) and 1 person on the other). 2. Someone who's learned at least the musketeer power claw trap (I don't know if this bug effects the other musketeer traps or not, but it for sure effects claw trap).
Now here's the steps to reproduce it.
1. Have the trap person place the claw trap down somewhere (preferably in front of one of lone players units to make it easier on them). 2. When its the trap persons teams turn, have that player (the trapper) flee the fight. The claw trap should then be invisible on both the battleboard and the field itself. 3. Have the lone player move one of their units (or themselves) onto the space where the trap was previously before the trapper fled. The trap should then activate and deal damage to the affected unit.
Note that I have no clue if this works in pve or not but I would assume that it does.
Hopefully you can fix this bug so that it doesn't happen to anyone else like it did to me. Thanks in advance.