Slow Page unloading

I try to understand the page unload behavior in Basic UI.
I use a customized page, with several Widgets - the page gets loaded quite fast.
However, when the page gets unloaded - when choosing the Settings for the menu - everything is noticeable delayed. It takes several seconds until the Settings menu gets displayed.
It seems the delay is caused by items retrieving persistent data before unloading the website.
I removed some widgets for testing and the unload time gets improved.
I’m just wondering this is a normal behavior, as I didn’t expect to see that persistent data gets retrieve when the page gets closed?!

Thanks Stefan

I’m using OH 4.3

@Lolodomo is the most familiar with this.