Nothing in our software does anything if you exit from the airport range, which is about 15 NM from the airport. It just stays silent in the background, waiting for you to enter in another airport and it's surely not doing anything to the sim textures.
You don't say which simulator you use, so it's very difficult to say what problem might be. On a 32 bit sim, it might just be a memory issue, likely caused by a memory hungry airplane, which you noticed at those airports, just because they are fairly big in memory occupation (not bigger than other similar airports), but enough to cause memory issues when used in combination with a memory hungry airplane.