i was using google colab on my web browser and was trying to set some keyboard shortcut on google colab. 

After that, my keyboard keep showing weird letters when i am typing. you can see it in this image - 

[![enter image description here][1]][1]

I tried to solve this by going to system preferences > keyboard. then setting shortcuts and input sources to defaults. but it is not working. I tried varies other approaches from articles on the internet but still couldn't able to fix it. 

can anyone help me to fix this problem?


mac version - macOS Mojave version 10.14.5

web browser - firefox version 74.0

just to clarify the problem is not totally related to the firefox browser. It is also happening when i am using any other applications on my system like text editor for writing code etc. it is a system wide problem. 



  [1]: https://i.sstatic.net/E42lB.png