I apologize in advance - this is just a rant.
But importing with Lightroom is an absolute bear. I can manually copy+paste from Explorer windows faster than the software can even preview let alone import. And then I can 'synchronize' faster than the import process.
I seriously cannot stand working with Lightroom. But there's no other software out there. And so I put money in your pocket, every month. To be frustrated. I just want to *import* images and movies. Lightroom misses movies 1/2 of the time. Another quarter of the time it moves or relocates the import-to folder, sometimes into a previously used folder, and all the while sometimes not. It's temperamental. Every setting needs to be double- or triple-checked. Export settings change on their own. Plugin settings change on their own.
Again, sorry. I hate ranting. But seriously, this software is impossible. I have to use it for work but it raises my blood pressure.
This is a user-to-user forum in which Adobe product developers are rarely seen. I suggest you post in the official Adobe feedback forum: Photoshop Lightroom | Photoshop Family Customer Community . Adobe does read every post there and sometimes responds.
I never have seen it changing import or export settings on it's own. If it's really just a rant, OK.
If you are also looking for help or assistance in solving your issues please let us know much more details of the issue as well as your exact version of LR and your OS.