Emoji selector not working properly

I discovered that you can insert emojis in any app, even non-gtk ones with the key combination Super + . followed by space. The emoji selector shows up, but when I select an emoji, it is not inserted in the text entry box. I have to find the emoji I want, look at its Unicode reference and then use ctrl + shift + u and enter the code manually.
Why is this happening?

Hi,

I use Ctrl + ; on any app text box. But this combination didn’t work on browser.

Thanks, but that only works in gtk apps. There is another way that is universal, but it is not working as it should. This question is about that.

I discovered that there is a bug in this emoji selector. Luckily, there is a workaround. After using Super + . followed by space, navigate to the desired emoji, but instead of pressing Enter, use Ctrl + Shift + c to copy the emoji to the clipboard. Then simply paste it where you wish. Not an elegant solution, but less clunky than memorising it unicode reference to use with ctrl + shift + u.