I had an issue with a teenage Sim choosing weird, extended routes every time he left the house to go to school, I believe that issue is caused by C grades as now he's back to straight A's he travels to and from the front of the house again. However, at the time I thought the house might have been glitched, so I saved it to the gallery, evicted the household, bulldozed the lot and moved them back in.
That was when I noticed there was no option to set the front door, it's on quite a high foundation and I had previously messed about with the front. Because when they first moved in the inside view of the front door dropped down completely because of the way the stairs had been placed, after moving the stairs and front porch I got the effect I was looking for (the walls stay up!) It's the huge estate house in Windenburg if anyone else has the same problem. I also moved it forwards slightly on the grid - it was all good with no problems until the I made his grades slip...
I wasn't sure what to do when I saw there was no option to set the front door, I checked all the exterior doors and none of them had the option, but then when all of the household where back inside the house I took another look at it and noticed the option to set the front door was there again. Sorry it's not a solution, but for me at least the bug fixed itself.
