Certain Doors not working or blocked

I have found some doors that are blocked or not working.

First of all, the trap door on the 3rd floor that I got to through a window, would not allow me to go down. Don't know if this is a thing that happens every once in awhile or it is just bugged completely and doesn't let you go through it.

The second, is a door in.. Agolian or something like that, where you have to go to remove of these monsters for this sprite or fairy or something. But I was trying to get into this one tower and this Felstep or something like that was blocking my path and wouldn't move for 5 minutes.

That is all.

Felstep is not that strong, despite his size.

But still, I don't want to get into a fight that could be prevented.