SQL Availability Group question to do with pinging listener when primary is shut down

Hi,

I have a 4 node SQL AG config where the primary should auto-fail to the secondary via synchronous data commit IF the primary goes offline.

So during testing we turned off the primary but the IP for the  listener can't be pinged...i expect a ping if the primary is off as the secondary should respond but it does not...

Can anyone advise how to trouble shoot this? There is no error in event viewer - where else can we look for some info on this please?

I'm a new SQL DBA so not sure which SQL error logs if any would have this info?

Please help! Thanks!