If you have exactly the right amount of logs but it doesn't fill the inventory on the last few logs for the level it will stop.
You need to make sure you have more than the necessary logs to level to ensure a full inventory on the last run for each level.
Ideally it should recognise that you are on the last selection of XP for your level and top up the inventory with the next level of logs.
Otherwise it's been great for me with oversight to get 1-60