Kiom, did you use the correct object for the bridge? Which bridge exactly, underground or above ground? If you place the bridge from the very beginning, can the hero walk across it without any problems?
In general, it's strange.
I placed it as a regular bridge (above ground, Order faction), and the hero could walk across it (after moving it with the SetObjectPosition command, it stopped working as a bridge; perhaps the path coordinates were messed up). When you place three parts of the bridge in the editor, it automatically transforms into 1 object with 1 set of coordinates.
P.S. Visually, moving the bridge worked as expected, it was a single object, but when trying to walk across it, the hero would pass through it and end up in the water.
Added after 46 seconds
If it's not too much trouble, could you describe what's in the last line of the scripts? I'm curious.
It blocks the hero's path if he doesn't have any active heroes; visually, it's for comfort (in this case)
Multiplayer: Господство, Извечное противостояние, Война за Магию, Торговая империя, Анатомия войны, Эксперимент
SingleScenario: Последний Рубеж, Трон, Элиралис, Вернуться домой!, Лабиринты разума
Campaign: Колонизация