Query param getting modified before reaching the target server.

[SivaGandadharV]

Hi @apigee team

I've created a new proxy for a GET api, which will do the following steps: 

1. A Get request with query param containing encrypted token will reach the APIGEE proxy. This token will have special characters which needs to be encoded.
2. I'm reading the query param using the ExtractVariable policy and saved it to context variables as token.
3. I've created a Javascript policy and used it to build the target endpoint which also will have the encoded query parameter token. (ex: api/v2/orders?token=encodedToken)
4. Deployed the proxy and from the trace I got to know that the variable token is fetched and encoded properly, the target endpoint created is also looking as expected and all the characters are placed properly. 
5. However from the trace, the request sent to target server looks different. some characters of the query param are getting replaced with different characters only in the request sent to the server. 

Where to check for this issue? I don't have any other created policies which will modify this target endpoint. How to make sure the endpoint doesn't gets modified and will be sent to the backend server without any character replacements.

Thanks in advance.