Steps to reproduce on KDE-Manjaro:
1.Input any text to konsole with subscript characters, like “echo aaaa₂bbbb”
2.Move the cursor around the subscript. You will notice that text shifts left and right when highlighting the subscript:
This is perfectly normal. The text shifts so as to accommodate the size of the block cursor. 
Doesn’t happen on Arch or Ubuntu. It’s a Manjaro bug.
Create a new user and see if you can reproduce it. If you can, then tell us what this “Manjaro bug” is so it can be fixed.
If you move the cursor all the way right and left, even the prompt gets scrambled:
On one user terminal this doesn’t happen. What can be the cause of this? It happens on all terminal emulators.