787 Production Slow Down (or stoppage) at Everett?

UPDATE (9/20/2017; 11:35PM): Matt Cawby just informed me that it appears that a 787 should roll out of 40-26 in the next few hours.  Prior to this roll out, Everett was assembling a 787 in 16 days.  This next aircraft (ZB220) took 22 days to assemble and thus still begs the questions as to why the assembly time has gone up from 16 days to 22 days? Additionally, Matt Cawby reported that ZB220 and the airplane that rolled out before that one (ZB276) didn't have their engines fitted thus I wonder if the hold up is due to Rolls Royce?

For the past few days I've noticed that Everett hasn't rolled out a Dreamliner since September 9th when ZB276 (LN 621, ET-AUO) a 787-9 was rolled out of the 40-26 building where the 787s are assembled.  Thus far in September, Boeing has rolled out 2 787s and started assembly on another 2 aircraft.

I don't know the reason why there has not been any further unloading (roll outs) of the 787s from the last assembly position 4 at Everett but the fact that Charleston is still turning out 787s on a regular basis does suggest that the reason doesn't seem to be related to design or assembly of the airplane in general though I wouldn't discount an assembly SNAFU on one or more of the airplanes currently in 40-26.

Typically, at Everett, once the 787 has completed work in position 4 it is rolled out to the 40-51 ramp where minor assembly tasks are completed.  The airplane then usually goes to the paint hangar or the fuel dock depending on the availability of the paint hangar.  It then follows the normal Boeing pre-flight ground testing followed by the flight tests and delivery.  According to Chris Edwards, a spotter at Everett, there hasn't been any 787 movements out of building 40-26 and confirmed that ZB220 (LN 623, HS-TWB), the next 787 to roll out is still inside.  Chris also noted that it took about 2 weeks to paint QANTAS' first 787-9 which is a long time for a livery as simple as QANTAS'.  There is a very small chance that the airplanes that were the next to roll out went straight the paint hangar but it would mean that Boeing would have had to complete all assembly tasks inside including minor ones and then roll it out.  I doubt that this has happened.

I'll keep watching this situation as report as circumstances warrant but it is too early to determine if this is a major issue and what, if any, impact this will have to the 787 delivery schedule.