Frontend JavaScript Bug Fixing - Character Display Issue

I'm in need of a skilled JavaScript developer to look into a bug I'm experiencing with a character counter in combination with a emoji picker (JQuery) on a textarea (JS).

The issue is that the character counter is not working as expected. Please see requirements.

Emoji Picker used:
https://github.com/mervick/emojionearea

Either fix counting with the given character counter script or use another one which works as expected.

Current problems to fix:
A. When deleting all chars counter shows 1 instead of 0 (on firefox browser, not on chrome)
B. Deleting all characters with mouse doesnt update count. In this case it should be zero then.
C: Page refresh or load doesnt show actual count.
D. Emojis are not count.
NICE TO HAVE:
C. Make maxlength also work for emojis. (If character limit is reached emojis still can be typed)

Don‘t change functions which are already added in code!!

Playground: https://jsfiddle.net/zxpuejkL/

The ideal freelancer for this job should be proficient in:
- JavaScript
- Debugging
- Experience with textarea scripts or char counters together with emoji picker.

The script needs to work seamlessly across both desktop and mobile browsers