You have rightly configured "FQDN for client acess" as View deployment's load balancer.
Few things you may want to try:
1. Can you login to view desktop directly from View Client via this load balancer. If yes, we need to look at Horizon Workspace side configuration
2. Is loadbalancer using default HTTPS port 443 ? Horizon needs all View Servers i.e. (View Connection/Replica Servers, Security Servers and Loadbalancers) to use default port 443
3.If its 443 , Try using IP of Loadbalancer and see if that works.
4. Also ensure that SAML is enabled and configured on all View Replica servers sitting behind your loadbalancer