Adventure Worlds bug with quests. Black bag

This happend when I returned home under a quest:

So, I kind of like traveling, and doing quest. But I am stuck on a quest. It's called "Black bag" ...something. You're supposed to hack a HQComputer that belongs to the restistance(Spelling).

When I found the house, I got two options: Ring the bell or sneak in. No one lived in the house, so I sneaked in. I turned off the stereo, and the "secret stairs" did open. I did the first puzzle and came to the second, but, while trying to solve it, I had to go home, because my time ran out.

Between this hometravel and my next travel I traveled to China 2 times. After that I went back to Egypt to try finishing the quest. But then I couldn't get into the house? The only option on the house was "Ring the bell", but I couldn't, because no one lives there. I had no clue to get in.

I tried the cheat "testingcheatsenabled true" to try to teleport in. But couldn't target the ground. (While holding shift and clicking the ground, I got 2 options, if I wanted to build or buy on the plot.) I then tried to remove the door + wall to get in, which worked. But I couldn't use anything in there, including the stairs. So it was kind of useless.

I builded stairs from the bottom of the HQ to the top, so now there was stairs outside of the house, but I could still not use it.

This makes me very annoyed, and I wish that someone know if there is anyway to fix it. 🙂 And how to prevent it in future. (I guess it oculd be to not start a quest when having 8h left on the travel or something)

Sorry for my not very good English, but I think it's understandable? :P

Greetings