How is my software conecting on my SQL Server if it failover via availability groups?
I'm trying to connect via SSMS to the X.X.X.38 That is the CLUSTERs Ip but It shows the error that the instance cannot be found. 


Named instances, by default, don't listen on port 1433, which is required to connect without a specific port or instance name.

However Failover Cluster Instances always listen on dedicated IPs, so you can (and should) reconfigure your FCIs to listen on port 1433 using SQL Server Configuration Manager.

You can do the same thing if your instances are standalone (non-FCI), but you have to configure them to listen on specific IPs in the case you have multiple instances installed on a server.  If you have a single named instance installed on each server you can simply configure it to listen on port 1433 on all IPs.