Create AimOffset from C++ plugin issue

First, sorry for poor English.

I’m writing a plugin to automatically generate AimOffset.
It looks like this.
I finished all the copied AnimSequence assignments and PreviewBasePose settings, and thought I was done with all the work.
However, that AimOffset doesn’t work.
The seek bar does not move and the aim does not change even if you move the pointer.
However, if I reassign any one property from the asset editor it will work correctly.
What can I do to fix this?
I tried PostLoad, ValidateSampleData, PostEditChange, OnObjectPropertyChanged, etc. but it didn’t work.

Here’s the code I wrote.
If you want to try this plugin, use UE4.25Preview.

Somebody help me.

Thanks for reading.