When I have my pet out (with meso magnet) there always stays some money on the ground that my pet does not pick up. I can pick it up myself, but the pet doesn't. I'm not sure if more people have had this 'problem', but I thought I'd mention it anyway.
Yea this has happened to me. At first I thought maybe it was specifically to the Water Goblin map, but since you mention it I guess it happens more frequently.
I've had the problem mainly at the water goblin map, but it happens in other maps too. Although it does happen less frequently.
To me this happens when I jump down a stage via down+jump or when the mesos was out of my screen range.
This happens to me also. Maybe it has something to do with the timer on mesos/items that affect when others can loot them? Just a thought
I've noticed this happens after the mesos/items 'flash' on the screen, which happens sometimes when moving vertically within a map, be it jumping or changing platform. Horizontal movement seems to not affect it. An easy place to observe this is at Ghost Ship 2, when jumping from the middle stair to the top platform, if I recall correctly.