In the new maps (maybe in the old maps too idk) in murder mystery, a regular coin is being counted as 2 in the quest progress
Quest progress [56/60]
You found a coin
Quest progress [57/60]
Quest progress [58/60]
It doubles
Hey there 
Thank you for submitting a bug report.
I have logged this issue and it will be looked into by our developers soon.
Have a great day! 
This issue has been fixed 