Any request on the SageCRM Rest API gets redirected on the application server by IIS from "{server}/sdata/{installName}j/sagecrm2/-/{resource}" to "localhost:{port}/{installName}j/sagecrm2/-/{resource}". When returning from this request the respons contains a JSESSIONID cookie.

The path in this cookie is not correct: it reads: Path=/{installName}j
A browser (and maybe even a curl script) would not register this cookie (because path not correct), so a following request will create a new session and a new JSESSIONID Set-Cookie.
Creating a new session takes up extra time server-side, so responses get slower.

The cookie should read: Path=/sdata/{installName}j
I added an outbound rule to the rewrite in IIS that changed the cookie-path from /{installName}j to /sdata/{installName}j

Does anyone else figure this out? Is this a bug?