Bugs: Ordered List Malfunction Answered

I'm just regularly typing and use ordered list then it malfunction, as if the cursor doesn't locate to '1' and cannot be deleted.

1.) Windows 8.1 Pro
2.) Google Chrome
3.) https://www.instructables.com/editInstructable/edit/E7YZME5IR5MV53U/step/1
4.) Added Screen Shots
5.) It happens in repetitive use of Ordered List