Ah, got some good rides in on the new gravel bike.  So much fun.  But, a couple set-up questions.

One, is it my imagination or is my seat post slipping a bit over the course of a ride.  CF frame and CF seat post (my first CF frame).  Just seems like it is slipping a bit, or my legs get longer!  Is that common?  Is there a fix other than cranking down ever harder on the collar?

Two, related to one, when I have the seat at the height I like for leg extension, I seem to get a little tingle in my hands.  When I look, the seat is up there compared to the handlebars.  Should I be looking at adding spacers or a riser stem to address the tingling?  I am definitely leaning more on the bars than I do on my road bike. 

Thanks for your insights!