@crinrict I did some experimenting with this and found some interesting results. First off let me just say I only have access to base game locations, the only pack I have is Kids Room (because it was free with Game Pass) so I can't test other places. Also before I get into what I found, let me also just say that I personally could only replicate this at The Solar Flare. I could not get the same results on any other lot, and I tested all pre-existing base game community lots and several residential lots. To be more specific about my game version, it's 1.60.25.2300 and I'm using an Xbox One X.
So after reading what MzMelonz said I tried to see if my active sims would do the same thing, and they do. So basically any sim (inactive sims included) trying to leave the lot by means of walking off of it has a chance to glitch when trying to use the stairs. As mentioned already one possible result is that they walk down and then reset, cancelling out the interaction to leave, but that's not the only result I found. Sometimes sims just bypass the stairs altogether, and just basically teleport down somewhere in the vicinity of them while also cancelling out the interaction to leave. I've noticed a lot of sims will get to the bottom of the stairs then stop for a few seconds before continuing on, though this doesn't seem to cancel anything. I saw several inactive sims walk downstairs, stop, walk back upstairs, stop again, then finally walk back down and leave.
I also did some experiments with the building and lot. I first tried deleting the stairs and replacing them with different ones, didn't help. I then flipped the stairs around in a 180 degree rotation to see if that would help, nope. I tried to completely delete that entry room at the bottom of the stairs, nope. I tried replacing the stairs with the classic wooden ladder, and I didn't notice any issues. I also tried going into my library and placing that version of The Solar Flare over the existing one, didn't help. I then took that same version from the library and placed it on a different and empty lot, no problems. With that attempt I noticed sims were using the door off to the side of the stairs, so out of curiosity I went back to the default location for The Solar Flare and tried another experiment. I removed the door facing the road, forcing sims to use that one to the side of the stairs, and I didn't notice any problems. I also tried replacing The Solar Flare with a different type of community lot, the gym with the big staircase (Movers & Shakers), and had no issues.
I'm not sure how helpful any of this could be, though I figured I would share it since the results seem pretty weird to me. OH, almost forgot. I also experimented many many times to see if it would happen just by commanding a sim to go down the stairs, and the only time it would happen was when using the Go Home interaction.
@MzMelonz I don't mean this to seek sympathy or anything, and I'm certainly not using it as a way to mock others in a similar situation, but I simply don't have a life and I'm not in a very good place overall so for me being able do things like that are great ways to distract myself and get my mind in a better place even if just temporarily. It certainly wasn't very fun sitting for who knows how long and watching characters walk downstairs, but hey if it can potentially help anyone and also get my mind of off the crappy things then as Beavis and Butt-Head used to say... "we're there dude" lol. Plus listening to music as I experimented helped significantly.
I do think I need to try more experiments now though. When I replaced The Solar Flare with the gym I also switched the lot type to a gym, so I think I need to test just changing the lot type to see whether or not the lot type does actually impact things in any way. One other thing I feel I should test is in regards to when I tried moving The Solar Flare to an empty lot. In it's default location I tested whether or not the sims would glitch when they only had the side door to use, but when I tried moving the place to the empty lot sims were only using the side door and I didn't test the front one.
@MzMelonz Thank you, I appreciate that, though it's been too long and I pretty much gave up long ago.
Back on topic, I tried changing the lot type of the Solar Flare to a gym without actually changing anything about the place (I did add in some exercise equipment and showers to meet the lot requirements though) and I was still getting the glitch. I also tried changing Movers & Shakers to a lounge type, adding in the required lounge items, and I didn't see any problems with the stairs there. So I have to guess that certain lots, or at least the buildings on them, have some sort of routing issue going on when leaving the area. I'm still not entirely sure though, and I'm starting to doubt if some of the tests I did were good enough.
I ended up turning the Solar Flare into a single floor building, and moved all the things on the main floor to ground level. I originally did it for fun, but seeing as how it eliminates that glitch I ended up saving it to my library and using it in my main save.
