After certain updates, it seems autodiscover url can get removed from the existing config, the below will re-configure it. Commands are to be used in the Exchange Management Shell

Set-ClientAccessService -Identity "HOSTNAME" -AutoDiscoverServiceInternalUri https://mail.XX.com/Autodiscover/Autodiscover.xml

This will list the current autodiscover url

Get-clientAccessServer | fl Name,AutoDiscoverServiceInternalUri

This will list all exchange services url’s

$virtdirs = "ECP,OWA,OAB,WebServices,Activesync,autodiscover,mapi"
$array = $virtdirs.split(",")
foreach ($i in $array) {
$j = "Get-"+$i+"VirtualDirectory"+" | fl name,server,internalurl,externalurl"
iex $j
}