Speed of the nodal axis

[Ava]

On July, 10, 2018, true north node was @ 5°59 Leo, according to astro.com's ephemeris. 

Its last day in the 5° Leo range is the 12th of September. 

So the transiting NN spent two months on the same degree:

www.astro.com/swisseph/ae/2000/ae_2018.pdf

But the NN spends only about two weeks on each subsequent degree. 

Does anyone know why this is the case?

Does it have something to do with the eclipse season?

[Deleted]

My only thought is that Mars has also been retrograding over that similar degree since late April.. I have no idea if there's any correlation there, so hopefully a more seasoned astrologer can correct me

[lumina]

I think the different speed is because of the nodal axis having gone direct at some times; this does not happen totally often, but occasionally, and if it does, the speed of course seems to slow down.