I am installing 3 Kasa Tp link smart switches in one box. After installing, two fixtures work and one fixture just blinks on and off constantly. Original installation had a dimmer on this switch with only two black lines coming out of the dimmer. I swapped a kasa smart dimmer and a regular smart switch and they both have that blinking problem while the other two switches work fine.
I will attach a very rudimentary drawing lol. Since originally the line going to the dining room light didn’t have a neutral I just tied in with the neutral line on the other lines.
Thank you everyone for any help.