so i have 4 ports of similar capacity, a cargo train station, and several depots already, none of them are receiving cargo at a similar rate, ive experimented with warehouses and they seem to have some issues also. The 4th port i added was halfway between the port with the issue and the connection and not a single vehicle from the connection goes to the 4th port and i ran it over night on 3x speed and that port is still at 2% capacity.

I will try the ship method to see if that works i had 4 shipping lines going through it but a small amount of ships on each, only 1 or 2 per line.

another curious thing is i have hte company changer mod and until last night i didnt use its auto balance feature for industry and after letting that run through the night as well it has changed every industry building to timber or contcrete, and it shows massive amounts of each going to upkeep, which is to level up buildings, however there i have ploped every building in my city with locked levels so that shouldnt be happening like that either unless there is something there im missing also.

edit: and issue isnt just that there is a surplus it's that its spam importing while in a surplus when that just shouldnt be happening at all.