Kong Proxy routes doesn't work consistently

Hi Team,

I have configured Kong routes with actual API end points but the connection is not persist in Kong and it throws 404 error (404 22 “-” “python-requests/2.19.1”) for APIs. Kong proxy return a data not consistently. Sometime API return data and sometime it is not.

Under Kong log details below error are logged. What would be the issue/reason behind it.

Error Logs:
10.128.3.78 - - [23/Dec/2021:13:25:41 +0000] “GET /Service-1 HTTP/1.1” 404 22 “-” “python-requests/2.19.1”
10.128.3.92 - - [23/Dec/2021:13:31:04 +0000] “GET /Service-2/ HTTP/1.1” 404 22 “-” “-”
10.129.4.17 - - [23/Dec/2021:13:32:36 +0000] “POST /Service-3 HTTP/1.1” 404 22 “-” “python-requests/2.22.0”
10.129.8.2 - - [24/Dec/2021:12:27:20 +0000] “GET /Service-4/?apikey=xxx-xxx-xxx-xxx-xxx HTTP/2.0” 400 5926 “-” “Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36”
10.129.8.2 - - [24/Dec/2021:12:27:20 +0000] “GET /css/bootstrap.min.css HTTP/2.0” 404 48 “https://Service-5/?apikey=e087be63-a8c1-49f4-9cbc-617565d3ea4b” “Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36”

Thanks,
Pallav