Prerequisites¶
One page tree per country ("country branch")
Root of each country branch has the option "Use as Root Page" set
Crosslinks between the country branches work. Perhaps you have to set config.typolinkCheckRootline = 1 and config.typolinkEnableLinksAcrossDomains = 1 in your TypoScript setup.
If you have MountPages, try to set config.MP_disableTypolinkClosestMPvalue = 1 in your TypoScript setup.
If you activated the EXT:seo (typo3/cms-seo), you should disable it's hreflang generation
in TYPO3 9.5LTS with unset($GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['TYPO3CMSFrontendPagePageGenerator']['generateMetaTags']['hreflang']); in the AdditionalConfiguration.php or your Theme-Extension's ext_localconf.php
in TYPO3 10.4LTS by not setting hreflang in your site config languages (or wait for EXT:bgm_hreflang version 5 :-))
Since version 4.0 you have to use the new page translation without the table "pages_language_overlay"!