I see the following warning locally when submitting the form on Special:ExpandTemplates:
Deprecated: Use of MediaWiki\Output\OutputPage::setCategoryLinks was deprecated in MediaWiki 1.43. [Called from MediaWiki\Specials\SpecialExpandTemplates::showHtmlPreview in /var/www/html/w/includes/specials/SpecialExpandTemplates.php at line 280] in /var/www/html/w/includes/debug/MWDebug.php on line 385
It was deprecated in rMW3739467256f3: Deprecate OutputPage::setCategoryLinks() for T373480: Display categories in sorted order by default.