First of all - great results so far!! Looks very pretty!!

As for curls under and waves over - that's actually really common. A lot of people have a mix of curl/wave patterns. My hair is probably mostly a 3a, but on top it's a mix of 3a/2c, and underneath it's 3a/3b.

Yes, straightening, chemicals, even sun and air pollution can all effect the canopy and make the wave pattern weaker. Sometimes it's a combination of that and your natural mixed pattern. That's what I'm finding it is for me, but CG has made it equalize a lot more than what it used to be.

I've been CG for a year now, and I'm still learning, and my hair is still improving. You are already seeing progress after 3mos - wait until 6 or 9mos!!
2c/3a/3b, Fine/med, Dense, high porous, & normal elas.

Lo-poo - Renpure Keratin, SMR, Giovanni SaS
clarifying - mix Johnson's H2T with low poo
Co-wash - Suave Nats. clar. or coco.
RO - GVPCB, Ion Eff. Care, TN.
LI - SMR, Cure Care, or RO
Seal - MO or Jojoba
DT - + honey, ACV, & EVOO to SM masque & GVPCB
PT - Gelatin!, CNPF
Styling - FSG, AIF, BRHG, LALS/PS, GF curl spray gel, SM Souffle/Smoothie, LOOB
Oils - MO!, EVOO, jojoba, GSO, SM Elixer, EVCO, VO5 Hairdressing