please add a screenshot.

ensure that in designer mode you have the calculated value control sufficiently wide enough to display the expected value.

That's the issue, I cannot expand the width ,I can only expand the height

why can you not expand the width?  please screenshot what the control looks like in designer.

maybe this will help?

https://community.nintex.com/message/39069

Since I am having multiple textboxes in repeating  section I cant increase the width. Following is the screenshot where I am placing calculated value behind the textboxes

Thanks for the reply,I had a css which modifies the size of repeating section which is causing the issue