Woocommerce REST API JSON Error URGENT

I have a problem with Rest Api, I am using Automattic Woocommerce Rest Api to search categories, I am getting this error:

PHP Fatal error:  Uncaught Automattic\WooCommerce\HttpClient\HttpClientException: JSON ERROR: Syntax error

This is my configuration for api

$woocommerce = new Client(
    'https://url',
    'ck_xxxxxxxxxxxxxx',
    'cs_xxxxxxxxxxxxx',
    [
        'version' => 'wc/v3',
        'timeout' => 0
    ]
);

I am sending GET Request $woocommerce->get('products/categories?search=E?itim Hizmeti');
it returs json syntax error,the problem is it returns error for specific search string for example if i use above string it will return error but if i will use this $woocommerce->get('products/categories?search=Acil Durum & Güvenlik Ekipman');
it will give perfect response without error, for the first request I get body as html 400 bad request cloudflare, I tried to close cloudflare and it still gives me the same error, I checked permalinks and it is okay, I deactivated some plugins still get this error, I tested both request in postman it works perfectly, then I tested with different server and url both request works.
If someone has solution I would be appreciative, I spend almost 2 days to find a problem where does it come from.