AWS ALB endpoint returns 404

I have an interesting situation going on right now.

IF                                        THEN
Host is example.com                       Forward to:
Path is /abc?/*                           <load balancer URL1>

IF                                        THEN
Host is example.com                       Forward to:
Path is /*                                <load balancer URL1>

There are two target groups and both of them are healthy. When I try to hit example.com/abc1/something-> this works with no issue. But, When I try to hit <load balancer URL1>/abc1/something-> this throws 404 error.

Q1: How does example.com/abc1/something is working if the load balancer is failing.

Q2: Few endpoints are just not working and returning 504 errors even though target groups are healthy.