TYPO3 Core

If you flush the cache of a page with hreflang tags and a language menu the query parameters of the first request are cached and used for subsequent requests to that page, even if other query parameters are present in the URL.

In other issues (such as https://forge.typo3.org/issues/88264 ) it's suggested to add those parameters to the cHash white list. This is not desirable in all cases.
If for example a solr result plugin is displayed on the page then the search query and the facet parameters should not be included in the cHash (that would flood the cache) but these parameters should be part of the hreflang tags and the language menu.
Currently the parameters used with the first request for that page after flushing the cache are used for the hreflang tags and the language menu of future requests to the page. If you select other facets or visit the page without any parameters then the cached parameters are also used.