My curls tend to fall and lose definition if I've over-conditioned or have used super-moisturizing conditioners, treatments or styling products.
Just my two cents.
Hair Type: 3A/3B; natural color; mid-back length.
Daily: CO Wash - V05 Kiwi Lime.
As Needed: Giovanni 50:50 Balancing Shampoo.
Fave Conditioners: KCKT Leave-In; Jessicurl Too Shea; HE Hello Hydration; Wen 613.
Styling Routine: Squish-scrunch product /conditioner into soaking wet, upside down hair; plop for 5-10 minutes, then air dry. (Diffuser dry occasionally.)
Fave Styling Products: Jessicurl CC; various conditioners as styling product; LA Looks Sport Gel.