problem with using 3d Widget slider to control Sky light multiple cubemap blends.

Hi guys, I am recently working on a VR project, now I am working on a function that uses a slider to control the day/night circle. I am hoping the get the effect like in “google earth”.
I used the “OnValueChanged” on the widget to get the value and interface to connect it to the skylight cubemap blends fraction. It works well with only two cube maps.
But I wanted to have multiple cubemaps for different time of a day, so I connected the “in range” note to value of slider to determine which map to load, but the problem is when the map switching it has this poping and flikering effect, it is not the smooth transition that I need.
Also use the “onValueCHanged” event to rotation the directional light causes a flikering effect too.
I wonder if there is any other ways to approach this?
Thank you very much.

widget graph:

skylight blueprint: