I have noticed that CustomDepth was working perfectly in Editor If I enable it in Editor, but doesnt work during Gameplay when I spawn because CustomDepth is disabled from the begining and I activate it once I press V using two nodes: Set Render Custom Depth and Set Custom Depth Stencil Value to make it not visible when you start and only visible when you press V. So I tested enabling it by default and it also worked during gameplay.
My solution have been enabling CustomDepth from the start after the map is loaded and add a delay of 10 seconds in Event BeginPlay.
After that delay, I set Render CustomDepth to disabled so its not visible.
From now, when I press V to set Render CustomDepth to enabled, plants doesnt blink as in my video