That's one of the issues caused by using debug tools like MOO and why the devs removed a lot of their game build tool cheats from the game. But that has been an issue off and on with moo in particular since Sims 3 especially it seemed on placed or turned lots in particular. That is one of the reasons why if I down load a house where moo was used previously, especially if moo was left on throughout the build, it is not always cut and dried that you can just remove everything and it will be alright. Devs warn about leaving cheats on - as things caused by cheats - especially debug cheats - do eventually mess up some save and games. It is the risk you take to use devs tools - so expecting them to fix it - usually isn't possible. You generally have to get rid of the builds as well as that save - preferably restart the whole game to be assured the issue does not return.
Like Grant posted their tools can cause real damage - if left on for extended periods of time - moo has always been that kind of tool - where it works great for the longest time - and then all of a sudden the game goes to pot. First just one house - eventually several. Hopefully it is just that house or that lot.
It is the risk you take using developers tools. As for fixing it - well lets put it this way the last time MOO actually worked as designed was in Sims 2 where it was originally used for a lot more than just placement of item - it used to be a reset tool and a number of other things - but even then it was imperative you turned it off after every use, and turned it back off again immediately - as it affects all content when it is in an on state as technically you are off grid in the on state..