Bug

Problem:
After upgrading to WPML Multilingual CMS 4.9.7 and WPML String Translation 3.5.4, [wpml-string] shortcodes wrapping HTML elements like

<input>

or

<textarea>

cause these elements to disappear from the page output. This issue does not occur with the previous versions WPML 4.9.6 / String Translation 3.5.3.
Solution:
We confirmed that this issue is specific to WPML core / String Translation 4.9.7 / 3.5.4 and is reproducible on a fresh WordPress + WPML install without any theme or plugin customizations. It appears that a change in how shortcode-wrapped HTML content is sanitized, possibly related to a security hardening pass mentioned in the WPML 4.9.7 release notes, is causing the problem. We have escalated this issue to our 2nd tier support for further investigation. If you're experiencing this issue, we recommend checking if your site's behavior matches this scenario and consider holding back your production environment on the older version pair (WPML 4.9.6 / String Translation 3.5.3) until a fix is confirmed.

Please note that this solution might be outdated or not applicable to your specific case. We highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If the issue persists, please open a new support ticket at WPML support forum.