Exiting Apartment In San Myshuno Not Working

Hi, I've been getting an odd bug recently.

I created a family with a dog whom I located in one of the apartments in San Myshuno. Everything seemed fine until all of a sudden, when my Sim took his dog on a leash, I ordered him to take him out and instead of going towards the door and then the elevator, the Sim suddenly went towards the corner of the apartment - paralel to the place outside I chose for the dog to empty her bladder in - and the Sim's bubble showed he had no way out. Command "Go down" on the elevator resulted in the same thing - they didn't even go in the direction of the elevator, only to the corner.

I had to move them out of the apartment but, incidentally, after the same amount of time, so during the second winter at that place, the bug reappeared. This time, I think I witnessed the bug being created? I mean, my Sim suddenly came back from letting the dog to empty her bladder not through the elevator and the door, but suddenly walked in through the corner of the apartment (so basically through a wall), yet again paralel to the spot outside I chose for the dog to pee. After that, the bug with taking the wrong direction and essentially not being able to exit the apartment (unless travelling to other places but that's too much work to just let your dog pee) reappeared and stayed. 

I tried reinstating an old save but the bug was there, even though it wasn't at the time of the save, and I did the "Fix" thing on the game but to no avail. No amount of restarts helps.

Any suggestions?

Thank you in advance.