Firstly let me apologise for the slow response, we aim for a lot better but have an unexpected busy spell coincide with a few holiday absences.
Regarding your issue, we are talking about using this, yes?
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I note from our internal tickets that we used to list compatibility with the XTM WPML Connector plugin, but this broke a couple of years ago and it has not been added back.
I'm not familiar with it, can you please describe where these xtm-wpml-connector custom HTML elements with the CDATA content come from and the steps to reproduce the problem?
As I don't have access to that plugin—for which I assume you need a connected XTM account—could I invite you to set up a demo where the problem can be reproduced on one of our sandbox sites?
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