Hey, Beesan, good to see you again. 

It could be coming from the weight of your hair or it might just be your unique curl pattern.

The top layer of my hair has soft big S waves.  Under that, for most of the rest are smaller S waves and some spirals.  Then, the hair at the nape right at the hairline has almost no wave at all. 

That's why I mostly wear my hair 1/2 up, 'cause I want to show off the pretty part and camoflauge the top.  Of course, Susan's hairsticks make my disguise so much more enjoyable!!

I also wanted to add that for me, the longer my hair gets the more curl pattern shows up.

If you want to encourage the top to be more wavy/curly, after your final rinse, bend forward at the waist and look at the floor-do notturn your head upside down.  Scrunch your hair (I scrunch in a leave in conditioner from Devachan) toward the center of the top of your head.  Also using a microfiber towel helps so the weight of the wet hair doesn't drag out the curl.  Then I repeat bending forward after towel scruching and scrunch in some gel from Ouidad Quench line.  Then I stand up and spray on an anti-frizz called Set It Free (Devachan) and scrunch that in  standing up to adjust the top layer.  You can see the result in my avatar-I always use the same techinque even though sometimes I switch up product but I guess I always use the same leave in, gel and anti-frizz.

Good Luck!!!

Glad to see you around again Beesan!

Hair can change.  I used to have stick straight hair when I was in my teens and twenties.  Once I had my son, waves started apearing.  I now have signficant waves in my hair.

Maybe it is just your "time" for your hair to change and the cuts have made it more obvious.