polylang wrong canonical on multi domain

Hello,

Thank you for contacting Rank Math and bringing your concern to our attention. I’m sorry for any inconvenience this issue may have caused you.

Unfortunately, Polylang is not yet fully compatible with Rank Math. The reason you are having the issue is that translated URL canonical is not similar to the translated page URL. You can check this list for compatible products with Rank Math:
https://rankmath.com/compatibility/

However, if you want to force the canonical on the homepage, you can explicitly set it in the Advanced tab of the SEO Meta Box. Even if the value grayed out in this field seems correct, please add the value you want to set as canonical

I hope that helps.

Thank you, and please don’t hesitate to contact us anytime if you need further assistance with anything else.

Hello,

We have been trying to collaborate with them for a few years but left the conversation when they refused to add the compatibility even though they have it for several other plugins (some of them have a smaller user-base compared to RM)
https://github.com/polylang/polylang/tree/master/integrations

You can check their public repository where we created a pull request (linked to from your opening post) a few years back and we would have maintained it (though that would not have happened ideally since we do not make changes in the plugin that breaks the compatibility).

Disappointingly, the compatibility needs to be added in their plugin as they added for other SEO plugins. We are more than committed to making that happen and always keep it updated, of course, if their team agreed and wanted to collaborate.

With that said, you can check the following page for alternatives that are 100% compatible with the Rank Math SEO plugin
https://rankmath.com/compatibility/
https://rankmath.com/compatibility/?s=Translate&post_type=rm_compatible

Hope that helps. Let us know if you need any other assistance.