The documentation states that "geopoly_within(P1,P2) function returns a non-zero integer if P2 is completely contained within P1". In fact it is vice-versa:

sqlite> select geopoly_within('[[0,0],[3,0],[3,3],[0,3],[0,0]]',
   ...> '[[1,1],[2,1],[2,2],[1,2],[1,1]]');
0
sqlite> select geopoly_within('[[1,1],[2,1],[2,2],[1,2],[1,1]]',
   ...> '[[0,0],[3,0],[3,3],[0,3],[0,0]]');
1
sqlite> select sqlite_version();
3.31.1