Irregular time slowdowns

[Porjate (OP)]

I've been getting a lot of slowdowns for quite some time now, and I can't figure out what could possibly be causing them.  It constantly reduces the 5 day increments, going as low as 20 hours occasionally but mostly swinging from 1 day to 3 days.  I thought it was caused by a hostile ship sitting in the middle of nowhere that was discovered due to a new deep space tracking station, but these interrupts are still occurring and I have no idea what they'd be caused by.

Should I just build level 10 DSTSs everywhere in an attempt to find these ships? Or could they be caused by some undiscovered alien race that is outpacing another race?

[Barkhorn]

Unless you can see one or more alien craft, it's probably NPR's fighting each other.  It's not getting down to 5 second increments, so the fighting is probably mostly positional.  Not much shooting, just both fleets jockeying for position.

[Porjate (OP)]

I had the NPR generation chance down to 15% for most of my game, and this slowdown has been going on for at least 20 years now; that's what made me suspect it was a scout ship hanging around my civilian shipping lines.  If it really is an NPR fighting another, then I feel this campaign may be dragging on a bit too long. . .  would it be possible for me to get them into combat by setting thousands of 5-sec auto increments? I'm willing to let my computer run for an entire night at that speed in an attempt to stop these slowdowns, repercussions be damned.

[Barkhorn]

It could just be a scout shadowing your ships somewhere too.  If it's been 20 years I find it pretty hard to believe that they haven't been spotted yet, unless your sensor tech is horrible.

[Garfunkel]

Or an NPR or a spoiler might have an listening post in a system that you civilians and/or fleet use.