We have resolved the issue for future text signatures, but the fix does not apply to existing text signatures that have the issue. As stated before, the PDF will display the correct characters once download.
Posted Feb 27, 2018 - 12:31 UTC
We have identified an issue of text signatures displaying as random characters once applied to a document. This issue is isolated to viewing the document in Nitro Cloud, if you download the PDF, the text will display correctly.
We are currently working on resolving the issue but do not currently have an estimated time.