Hi, I am trying to stretch and move the Deep_NWell from Ex-4c and it goes out of shape and even undoing doesn’t reset the shape. Any suggestions ?

I think by "out of shape" you are just referring to the DRC error patterns. They won't disappear as long as there is a DRC error; in this case it looks like you might have reduced the deep nwell size below the minimum (

drc find

and/or

drc why

will tell you what the error is).

This is happening when I’m trying to increase the size by using stret e 1um. Both the command outputs states no errors found

If the cell has been wiped of errors before saving, then it may not show DRC errors upon loading, until you change something.

drc why

will only report errors inside the cursor box, but I don't know why

drc find

states that there are no errors in a display that clearly shows errors.