When entering COGS and hitting the continue the figure for COGS is picked up from 2016 instead of 2017 and I can't get it to change that. What now?

The ending inventory for 2016 that is transferred forward should correctly be the beginning 2017 inventory which is the correct thing to happen.  Then you will add inventory added and the 2017 year end inventory amount to calculate the COGS for 2017.

That is exactly what I did and the Inventory for 2017 carries forward as the old 2016 number. It hasn't changed. That is the problem.

On this screen the 2016 ending inventory should be entered as the beginning 2017 inventory ... then you must enter the ending 2017 inventory on the second line.  These could be the same amount but not usually.  Then on the next screen you will enter the purchases during the year.