Back to bug reports, starting with 2 possible movement lock spots.
1st, found in top of frontier peak (highest point), player is able to walk on top of the lower whirlwind spot, dropping 1 layer and getting movement trapped.
2nd, player is able to trap Guilmon to a horny jail in the town garden. By moving in side steps (Down & left here), one can enter the small 2 spot fenced area and be caged.
Then the new boss (Bounty?) fighting on the overworld, not sure what triggers the error. In a clear casual run the fight worked as intended.
But using older saves the fight seems to start an error.