Additional Fields are working but there are extra characters on the TY Page

During checkout, the additional fields via Checkout Manager work fine, but after checkout, on the Thank You page, there are additional characters included in the input on the added fields (part of the link I added on the field title).

Please refer to this image that I uploaded on a test site so you can see the error: https://staging.piagladysperey.com/wp-content/uploads/2017/08/Capture.png

Please assist! Thanks! ??

The page I need help with: [log in to see the link]