Changing Languages problem

There is something weird going on when changing betweeen languges.
The URLs are not being formed correctly and the user is switched language and routed to the home page.
I am certain the issue is SEO configuration, but I am not seeing it.

Using the About Us as a test page here is what happens:
English: https://harbor-sales.com/en/information/about-us
Spanish: https://harbor-sales.com/information/es/about-us
German https://harbor-sales.com/information/de/about-us

So far, that looks right. Now, chanve from Geerman to Spanish:
https://harbor-sales.com//ueber-uns?language=es-es

The language changes to Spanish ok, but there is no ueber-uns page.
It is grabbbing the German SEO and slotting it in, along with two slashes

Going to a Spanish page and changing to English for example:
https://harbor-sales.com/Sobre-nosotros ... uage=en-gb

Again it fails because there is no Sobre-nosotrosx page'

The issue is SEO. Hoping someone recognizes this behavior and can point me to where to control it.
As always, thanks in advance for any and all constructive solutions
You are welcome to visit harbor-sales.com and test the behavior yourself

OpenCart 4.0.2.2

Dave

As a constructive suggestion would be to upgrade to the latest Opencart 4 version.
The most constructive suggestion would be to downgrade to Opencart 3.0.4.0.

Opencart 4 has many issues. Some known, some unknown and many unfixed.
Whilst developers are working through them to try to get a stable Opencart 4 version suitable for live sites, nothing exists.

Opencart 3.0.4.0 is compatible with php 8, has all the security updates.

Back on this unresolved problem.
Trying again, hopefully with better results

The problem is the NavBar -- when you change languages it does not form a valid URL.
Fails to include the category in the URL that is created, so of course the URL call fails.

I can track it down, if I knew where to look.
Which routines control navbar repaint when you change language?
Can someone point me in the right direction?
Thanks

And back to the questions: did you follow the advices?

There were several SEO URL issues in OpenCart 4 which have been addressed since then. So, at the very least, do a re-install using version 4.1.0.3, and be ready to do a later update to the upcoming 4.1.0.4 because it will have some more bugfixes. OC 4.0.2.2 simply isn't stable enough for a live site. BTW.: The menu bar does not contain the information entries, the latter are usually in the footer. Hence, it looks like your are using a 3rd party modification.

If you want an instant stable release for a live site, go with OC 3.0.4.1.

Thank you
Good response and what I needed to know
Appreciate the assist