Dynamic Parameter default values keep resetting to "0.0" (Niagara)

hi,
I’m using ue 5.01 / niagara

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I set Dynamic Parameter “Edge_Opacity” default Value “1.0” in material like above.

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but, in niagara keeps setting Dynamic Parameter default value to “0.0”

is this a bug?

I added “1.0” to dynamic parameter in material to use as default but it’s pretty uncomfortable to use.

thanks in advance.