checked again, already on the current version 1.5, everything is fine. Try replaying from the beginning.

P.S. The problem can be solved if it exists, but it doesn't.

The problem still exists - even in version 1.6 (which isn't surprising, since the author didn't fix it, believing it doesn't exist).

I can suggest that the presence of Haven troops in the dwarf's army might influence the appearance of this problem (the enemy stopping a few steps from the dwarf castle).

I recommend considering adding an additional script to force an attack on the next day if the enemy, for one reason or another (let's say due to the proliferation of neutrals), doesn't reach the dwarf fortress.