I cropped the 5th node for double piña 10 days ag...

Hello ! The 1st pistils are a sign that the plants are in the stretch stage , that's mean they are supposed to grow taller the next 2 weeks so you should start to give them a bit more fertilizer en reach a 1.2 to 1.5 ec level ( you should grab an ec pen to check you ec/ppm level) to encourage the growth , so continue with the veg nuts during 2 weeks after the 1st pistils before you switch to the flowering nutrient as the plants will need nitrogen during the stretch stage. Auto are not really suposed to be topped/Hst even if most of them are responding well to these method , some will be more sensitive ( maybe yours are more sensitive but give them 2 weeks to see how they performs), with a regular strain you can let them veg longer but with autos when you loose time it's forever lost. As your plants are in stretch stage you shoulg give them 18h to 20h of light a day to make them bigger then in full flowering you will switch back to 16h light schedule. I hope it will help you 😁👍