1. Please post logs as text instead of screenshots.
2. As the logs say, it is an emulated latency that is added by default in debug mode. It helps developers write optimized code. In most cases there will be some latency between the clients and the server.
It is probably a mistake to do, but you can disable it with:
In this case that is not the reason but non-legacy debug mode runs with a different architecture to a release mode program and that adds a lot of code and a lot of performance overhead to its execution. Only ever test performance in release mode.
Also remember that in debug, the web server is single threaded. This can cause some issues too - eg if you are making async multiple requests to the web server some may time out. For example I have one page which loads a graph with 20+ sets of data that are loaded individually via REST, in debug I will see some data not load the first time.