Multi-Line Text Field Disappears on Subsequent Sign Upload

Our documents go through iterative signature processes over the course of several months, so it is not uncommon for us to upload the PDF of a previously signed document (containing multi-line text) for a subsequent signature.  We have done this before, but are suddenly finding that, when we re-upload for signature any file that contains a (previously signed) multi-line text field, the text that was contained in that field disappears and is no longer included in the digital file.  It is neither visible within Adobe Sign nor subsequently after download.

Is this a new bug?  Is there a workaround?

Thanks!