Emoji Keyboard not inserting emoji after pressing Enter

After opening the emoji keyboard with Ctrl + Cmd + Space, selecting an emoji and finally hitting enter, the emoji keyboard closes but nothing is inserted at my cursor.

A restart seems to fix this, but after some time the keyboard breaks again and I need to restart again.

Does anyone have an idea why this is happening?

This is on macOS High Sierra v10.13.6 (17G2307)

Thank you.

The Enter (Return) does not work on my MBA High Sierra and never did before.

I place the cursor where the emoji has to go, then double click on the Emoji of choice.

😎 🤫 🧐 👀

Pressing Enter seems to break the emoji picker. You can, however, press Down Enter to insert the first emoji. (Ctrl+N Enter will do the same thing, and might be easier to type, although harder to memorize.)

Just make sure not to press Enter before Down/Ctrl+N, or it'll refuse to respond to keyboard input (Esc will still dismiss it).