In the system map (F3) there's a 'activate space-time bubble in this system' checkbox if you're in SM mode.
If it really is relentless, you can go to each system you have a regular presence in, check this box, run a five day increment and see what happens. Most of the time, nothing should stop you from running these five day increments - if in one system they do get interrupted, you've found the system wherein a sensor outpost, some distant ship or whatever the heck it is that's coping a feel with its sensors, is located. Throughly screen that system and your problem should be solved.
If this doesn't help, it's entirely out of your sphere of influence. I've never been in designer mode, but at least with regular SM you can then be sure that it's some NPR exclusive occurance from them sensing one another regularly. The auto turn checkbox is the only thing that'll help you then, or start without any pre generated NPRs next time.