Web server protection skip filter but no rule ID

Hello,

I have trouble configuring WAF rule for one specific web server/service 

When I try to access service from inside on my pc I get 403  

[Sun Jan 07 19:40:08.983664 2024] [authz_core:error] [pid 22769:tid 140041007253248] [client 10.2.1.10:52039] AH01630: client denied by server configuration: proxy:balancer://6291e1d15895c7c47ef0a19ffbb799cd/web
[Sun Jan  7 19:40:08.982766 2024] timestamp="1704656408" srcip="10.2.1.10" localip="A.B.C.D" user="-" method="GET" statuscode="403" reason="-" extra="-" exceptions="-" duration="1466" url="/web" server="subdomain.example.com" referer="-" cookie="-" set-cookie="-" recvbytes="1395" sentbytes="586" protocol="HTTP/1.1" ctype="text/html" uagent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.0.0" querystring="" websocket_scheme="-" websocket_protocol="-" websocket_key="-" websocket_version="-" ruleid="29"
[Sun Jan 07 19:40:09.087611 2024] [authz_core:error] [pid 22769:tid 140041007253248] [client 10.2.1.10:52039] AH01630: client denied by server configuration: proxy:balancer://6291e1d15895c7c47ef0a19ffbb799cd/favicon.ico, referer: https://subdomain.example.hr/web
[Sun Jan  7 19:40:09.086954 2024] timestamp="1704656409" srcip="10.2.1.10" localip="A.B.C.D" user="-" method="GET" statuscode="403" reason="-" extra="-" exceptions="-" duration="1164" url="/favicon.ico" server="subdomain.example.com" referer="https://subdomain.example.hr/web" cookie="-" set-cookie="-" recvbytes="648" sentbytes="429" protocol="HTTP/1.1" ctype="text/html" uagent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.0.0" querystring="" websocket_scheme="-" websocket_protocol="-" websocket_key="-" websocket_version="-" ruleid="29"

In the same time, other machines on LAN, WIFI or WAN can access service normally. Strange thing is that when I reapply rule or restart WAF service I can access web page also for some time.

Anyone has idea where to start with troubleshooting?

Thank you,

Carlo