Mojave bug: auto completing words

Ever since I updated to Mojave I have had this issue.

Sometimes when I write a word (across all applications) it will fill out the word as I type, but only parts of it. Sometimes it is only adding double letters - either way it is writing gibberish words as i type and it is super frustrating breaking my flow of writing.

It is hard to describe exactly what is happening so I have linked to a gif. (https://giphy.com/gifs/47BwkyxxiJtRcxP1f1)

In the video I write the word 'Level' and it autocomplets to 'Levelevel'

Next word im writing 'Done' But before I get to the 'e' it adds an 'o' in between resulting in the word 'Donoe'

What I have done to try to fix it without results

• Disable autocomplete (system preference->Keyboard->Text) by unchecking 'Correct spelling automatically.
• I've also tried rebooting the machine several times.
• Disable Spelling and Grammer by right clicking on text

Any help you be much appreciated!

Specs:

MacOS Mojave (v. 10.14.1)

Macbook Air (13-inch, Early 2015)

1,6 GHz i5

8gb mem

Intel HD Graphics 6000 1536 MB