This has happened in 1.07, too. If you have started from 100% and have built up infra to e.g. 120% and you want to increase the production line to 200%, it seems that AoD is calculating 120% + your max. production line (in this case 100%), so it will allow you only to increase your infra production line to 80%. This means that you can only add 60% to your existing production line and have to start a new line for the last 20%.