Is the statue of uncertainty not in the switcg port?
I have lv10 in farming,combat and mining and 8 in foraging and fishing. In sewer there is no statue? Am I too early for it or is it not in the switch port?
Check your Switch version, which should be 1.5.4.2. This is equivalent to PC version 1.5.4, which contains Ginger Island. Also, Statue of Uncertainty is part of the game since 1.3.something. Both should be available on the current Switch version.
As another comment said, be sure to meet the requirements for Ginger Island. But the statue should appear as soon you have the sewers unlocked and the first profession chosen (which usually happens earlier).
Did you open an old save game? Maybe there are some update shenannigans?