Bing Results Per Page with 'en-us' search market

[Blobme]

Hi!

Everything is working except this :

$bing->setPreference('results_per_page', 50);

It gives me only 10 results with 'en-us' but it works with 'en-ca' or 'fr-fr' and other where I have 50 results.

This line below is working as I'm in 'en-us' search market:
$bing->setPreference('search_market', 'en-us');

I think the problem comes from the request :
https://www.bing.com/account/?rpp=50&pref_sbmt=1&ru=/&GUID=xxxxxxxxxxxx&uid=xxxxxxx&sid=xxxxxxxxxxxxxx

maybe the GUID sent by Bing is not good and then it can't verify the cookie...

The cookie is created in C:\Windows\Temp
I'm in local with wamp and PHP 7.3.12

Do you have the same problem?
Thanks