When upgrading the sheep equivalent (trading) to 3 levels (should grant 2:1 trading with any resource), it doesn’t. This needs to be fixed so that trading is on par with ore and wood equivalents of any 1 resource when you don’t hit rolls or being able to upgrade to lvl 3 knights.
This isnt an error. Lvl3 in trade gives you the ability trade “Commodities” 2:1 with the bank and not resources. If you want to trade 2:1 resources with bank, you will need a 2:1 port. I hope you realise “Colonist” is a board game that came out in 1995 called Catan and all of this is in the rulebook.