Performance issues - Opening one page sends many request on backend console, Why is this?

[Mon Apr 11 18:19:48 2022] 127.0.0.1:54561 Closing
[Mon Apr 11 18:19:48 2022] 127.0.0.1:54563 Closing
[Mon Apr 11 18:19:48 2022] 127.0.0.1:54564 Closing
[Mon Apr 11 18:19:48 2022] 127.0.0.1:54566 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54566 [302]: GET /check-user-login
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54566 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54568 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54568 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54568 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54570 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54570 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54570 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54572 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54572 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54572 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54574 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54574 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54574 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54580 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54580 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54580 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54582 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54582 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54582 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54584 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54584 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54584 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54586 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54586 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54586 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54588 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54588 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54588 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54590 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54590 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54590 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54592 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54592 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54592 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54594 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54594 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54594 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54596 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54596 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54596 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54598 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54598 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54598 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54600 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54600 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54600 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54602 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54602 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54602 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54604 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54604 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54604 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54606 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54606 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54606 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54608 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54608 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54608 Closing
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54610 Accepted
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54610 [302]: GET /not-found
[Mon Apr 11 18:19:49 2022] 127.0.0.1:54610 Closing

looks like an infinite redirect loop to me. /not-found redirects to /not-found indefinitely.

But neither of the routes (/check-user-login & /not-found) seem to come from kirby core. More like from your config, site or plugins. So without further details it will be difficult to debug

Okay let me check /not-found route