[Resolved] Widget language switcher on WC checkout page: pay_for_order parameter missing

Hello.
We noticed that the language switcher widget is not working correctly on the WooCommerce checkout page.

Situation: We send emails from the WooCommerce admin area.
These emails go, for example, to customers whose payment fails and contain the payment link for the order.

By default, the payment link in the email is in the admin language.
This is often wrong.
We solved it with custom coding.

What we noticed: When a customer calls up the payment link, the pay_for_order parameter is missing in the language switcher widget links.
As a result, the customer cannot pay if he wants or has to change the language.
The translated link is incorrect.
It affects all links in the widget.
Even the language that the user is currently viewing in the frontend.

Page accessed:
- /en/checkout/order-pay/123/?pay_for_order=true&key=wc_order_xyz

Example widget links:
- EN: /en/checkout/order-pay/123/?key=wc_order_xyz
- FR: /fr/caisse/order-pay/123?key=wc_order_xyz
- DE: /kasse/order-pay/123?key=wc_order_xyz

The "pay_for_order" parameter is missing.

Note: I'm just talking about the widget language switcher, not the menu language switcher. I haven't tested the menu language switcher.
It doesn't matter in which language I initially call up the payment page. Always the same error.