I had this issue and it went away after I made all the pages that were involved Singletons in MauiProgram.cs

The issue for me was occurring after I nav'd away from the page w the Picker and back. The returned-to page's constructor was being hit on the way back and InitializeComponent ran. I guess that sorta created two Pickers. Dunno.

With the page as a Singleton the constructor does not get hit when it is nav'd back to. HTH.