Gangplank farm bug

In games where i am playing gangplank and farming very well, his farm gets lowered but it seems like the gold is the same. As far as i know this is just a visual bug but it is annoying to see inaccurate farm numbers at the end of game! The times ive been able to reproduce this is whenever i have 100 farm at 10 minutes, 200 at 20 and so on. It seems to bug whenever i get into the 3 and 4 hundreds for farm. Any help would be appreciated and im sure this is happened to a lot of other hard farming pirates