Inserting Symbols and Inserting Symbols with Keyboard Shortcut Don't Return Same Character. How to fix it?

Let's say I want to insert a symbol which is;

Font : Bookman Old Style
Unicode Name : Black Up-Pointing Triangle
Character Code : 25B2

Method 1 - Inserting Symbols (Insert - Symbol)

I select all on the sheet then select font at "Home - Font - Bookman Old Style"

I select a cell.

I go "Insert - Symbol - Font - Bookman Old Style"

Then choose the symbol which is;

Font : Bookman Old Style
Unicode Name : Black Up-Pointing Triangle
Character Code : 25B2

Insert. The returning character is black up-pointing triangle.

Method 2 - Inserting Symbols with Character Code

Now I want to insert same character with the keyboard shortcut.

The character code is 25b2.

I select a cell.

I press "alt" and type 25b2 on numeric keyboard part keys.

and a different character (black smiling face) is inserted.

Why the two is different? How to fix that?

Thanks