Steps to reproduce
Press CTRL+A to select an item. Then try to bold it with CTRL+B.
Expected result
The selection is bolded, just like it happens when you select the whole line by left clicking and dragging or using SHIFT and arrow keys.
Actual result
Instead of the whole text being bolded ** appears only on the right side.
Environment
Ubuntu + Firefox Nightly
Additional information
Italics, code, latex and other such actions also have this issue.