Treasure Hunt question

[John jacob astor]

i was asking the port locals to see if my max player treasure was at it's max and i got this message:

You asked the port locals spending 5 turns.
Your port maximum treasure has been increased by -39,725,000

why should this decrease my max treasure?? i understand the player with the max treasure must've taken out some gc, but why was i charged turns to decrease it? if i didn't update it and spend 5 turns, it would've been 40m larger. this doesn't seem right to use my turns to decrease it

[Captain Jack]

The port locals tend to be honest.

Which means that the treasure has been found or retrieved from that port.