TAdvSmoothTabPager delay on first show

Hi all.
This is the first time I have replaced a TPageControl with the TAdvSmoothTabPager to modernize the UI of an application.
Its use is really simple and similar to the TPageControl, with tabs, sheets, etc.
One thing, however, puzzles me.
When I start the application and first display a frame with the TAdvSmoothTabPager in it, previously already set up on the first sheet, there is a time "hole" where nothing appears and then you see the programmatically selected tab appear.
Is there any way to make it immediately active and displayed ?

Sample Video

Do you have more details, preferably a sample source project with which we can reproduce this here? So far, we could not see such issue here. Is there anything wrt connecting to a database or loading data that happens in the UI thread when this programmatic selection happens?

Actually I don't use database or any data loading.
The Form use some frame to keep clean the main form code.
The TAdvSmoothTabPager is placed in a frame, but the frame is created at Form creation and I switch to Frame visibility in 2nd time, so creation is already made by a lot of time.

My projects are enought complex to be simplified but I will try to create a sample which does not requires other 3rd party libraries as it is at the moment.

The "slowdown" appears ONLY at first control visualization where PageIndex is already set but client Sheet seem to wait end for animation before to be shown.

A sample source project with which we can reproduce this will definitely help for us to start investigating this.