Thank you for your reply.
I am using Windows 11. I have an US ANSI keyboard.
Strange that only the characters are being reformatted or converted in a few cases inside Obsidian.
And if I copy and paste those reformatted symbols, and paste on Notepad, the symbol is in the expanded form.
Also I a tested and checked on Notepad and Visual Studio Code, and the .md files are normally formated. I mean, the => are two characters.