Keycloak doesn't accept curl requests if the user-agent header is not one of browser user-agents

I have 4 different environments and 4 Keycloak server.
My Keycloak servers are installed on AWS EKS Kubernetes 1.22.
Keycloak 18.0.2
Chart Version 9.6.0
I don’t have any problems with 3 of my 4 Keycloak servers. All my installations are the same; only hostnames are different.
1 of my 4 Keycloak servers doesn’t accept curl requests if the user-agent header is empty. Please look at the situation below:

$ curl -I -A "Mozilla/5.0 (iPad; CPU OS 16_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/106.0.5249.92 Mobile/15E148 Safari/604.1"
HTTP/2 200
date: Fri, 14 Oct 2022 20:10:07 GMT
content-type: text/html;charset=utf-8
referrer-policy: no-referrer
x-frame-options: SAMEORIGIN
strict-transport-security: max-age=31536000; includeSubDomains
x-robots-tag: none
cache-control: no-cache, must-revalidate, no-transform, no-store
x-content-type-options: nosniff
content-security-policy: frame-src 'self'; frame-ancestors 'self'; object-src 'none';
x-xss-protection: 1; mode=block

$ curl -I
HTTP/2 403
server: awselb/2.0
date: Fri, 14 Oct 2022 20:10:17 GMT
content-type: text/html
content-length: 118

Could you please advise where I must look for the problem?

Thanks & Regrads