Slow response time of API Gateway

Product/components used and version/fix level are you on:

API GW 10.5

Detailed explanation of the problem:

Hi all,

I have a problem with our API Gateway. It adds a massive overhead in regards of the response time to the request. E.g. if I call some API directly without going through the API GW I have around 300ms response time. If I add the API GW to the path I get response times around 3s.
The interesting thing is that I only use one endpoint of the API that has 20-30 endpoints in total. If I delete all the other endpoints I can get down to around 330-350ms, which might be expected as the API GW is doing some logging.

Can anyone tell me why a “bigger API”, an API with more endpoints, slows down my REST calls this massively? Also tried with some dummy REST APIs where I just called a not existing endpoint. I just got a 404 by the API GW as expected but the API with more endpoints was much slower in regards to the response time.