I prepared a minimal example under https://en.wikipedia.org/wiki/User:Kallichore/Test?useparsoid=1

Steps to replicate the issue (include links if applicable):

• Create a tabular data page (JSON) where a field title includes the % character (e.g. "de": "1 %" )
• Embed the data on a wiki page
• Use the migration tool to compare the Legacy Parser with Parsoid

What happens?:

• Stray text (e.g. "%2 %3 %1 %2 %3 %Test") appears above the rendered chart in Parsoid.

What should have happened instead?:

• Parsoid should behave like the Legacy Parser

Other information (browser name/version, screenshots, etc.):

• The problem was reported first in de.Wikipedia under https://de.wikipedia.org/wiki/Wikipedia:Technik/Werkstatt#Falsche_Darstellung_von_Chart_mit_neuem_Parser
• I created a minimal example under https://commons.wikimedia.org/w/index.php?title=Data:Sandbox/Kallichore/Test2.chart and https://commons.wikimedia.org/w/index.php?title=Data:Sandbox/Kallichore/Test2.tab&action=edit that is called under https://en.wikipedia.org/w/index.php?title=User:Kallichore/Test&action=parsermigration-edit
• The problem disappears without the % in field titles.