Facebook doesn't display page title properly

Hello, I am guessing this is an easy problem to solve but apparently, I can’t figure it out.

When I post this link below, it shows the wrong title details.
https://www.cotoba-labo.com/

Currently, it says Demo:Home.
But it should have a Japanese title instead.

I thought it’s because the Page title is wrong but that has been fixed.
Can anyone tell me how I can correct this please?

Thank you!
Pascale