Sorry, but I hadn't seen the previous comments.

This fixed it:
(thanks AlexeyArder!

Begin quoted post:

I had changed Pages.php

public function translateShopUrl($url, $language)
...
if ($shopPageTranslation) {
...
// $shopPage->post_name, $shopPageTranslation->post_name, $url
$shopPage->post_name, $url

Now all work as expected

@Ketuax I also have not seen the previous comments.
What was the fix and why was it necessary? (as it seems to work for everyone else)
if we don't get the fix into the plugin you will have to re-apply it after next releases.

What is the final code you are using? as the quoted code is incomplete and incorrect syntax

Hi, here's what I did to fix the problem.

From this part of the code in pages.php

if ($shopPage) {
$shopPageTranslatedID = pll_get_post($shopPageID, $language);
$shopPageTranslation = get_post($shopPageTranslatedID);

        if ($shopPageTranslation) {
            $result = str_replace(
                    $shopPage->post_name, $shopPageTranslation->post_name, $url
            );
        }

I removed the word "Translation" from the last line.

The problem occurs when the page url contains the word "shop" as part of the company name. In my case it was Kypseli Workshop (www.kypseliworkshop.gr). Then the plugin goes and replaces the word "shop", with the slug translation.

I do not know php so I cannot say if this is correct coding but it solved my problem.

I hope this helps.

ok with that change that bit of code would do nothing, which only works in your case because the shop page in both languages has the same slug "shop", so this is not a general purpose fix.

What it should do is only replace the last occurrence of the post_name (or not at all if both post names are the same...)