Problem:
The language switcher is missing on custom taxonomy search.
Solution:
Client using outdated parent theme and lot of plugins, while child theme is heavily customized. We fixed the problem by adding the said taxonomy term and translating it once, but issue continues to appear on other terms.
We recommended the client to update parent theme, all plugins and check minimal.
Problem: The client reported that the language switcher was missing on both English and French search URLs, despite having added location translation and post translation.
Solution: We noticed that the search URLs were using a different template from the homepage. The homepage had a breadcrumb coming from an Elementor shortcode with a news-filter, whereas the search pages had a WooCommerce Breadcrumb. Since the client is using Elementor PRO, we advised ensuring that the same shortcode used on the homepage is also applied to the search/archive template.
If this solution does not seem relevant to your issue, please do not hesitate to open a new support ticket with us.