[LUCI] slow response form uhttpd server

I'm using lima I kit and build openWRT 23.05.4 form scrach and custom a page on luci web (using lua). This page send request every 1s, but response form server (uhttpd) very slow ( ~ 1,3 - 1,7 s with reponse size ~ 1000 byte). Kill some custom app on device make response faster ( reduce 100 -200ms). Top and see, no process is abnormal, cpu use ~ 40% .I debug in server, my code in server side done in 10 ms.. Anyone can help me fix this?

nice/renice, perhaps?