[Закрытые] WPML Language URL format change causes WSOD on Test/Production – JS error: WPML_core.sanitize is n...

Hello,

We are trying to change the WPML Language URL format from:
“A different domain per language”
to
“Different languages in directories”

Environments:
POC (works): скрытая ссылка
Test (issue): скрытая ссылка
Production (issue): скрытая ссылка

Issue on Test/Prod:
Selecting the option does nothing (no loader, no sub-options appear).
On Save → page reloads → White Screen of Death.
Setting remains unchanged.
Console Error:
Uncaught TypeError: WPML_core.sanitize is not a function

All WPML plugins on sites are up-to-date:

WPML CMS
String Translation
ACF Multilingual
CF7 Multilingual
WPML SEO

Same codebase works on POC but fails on Test/Prod.

Please advise what may cause this JS error and how to resolve it.