XMLRPC Error after Upgrading to 25.07

[KKIT]

I have two XG7100-1U Units which worked without problems in failover.
After upgrading to 25.07 from 24.11, I am getting the following errors:

XMLRPC Error
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-06 18:00:50
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-06 19:00:49
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-06 20:00:47
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-06 21:00:47
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-06 22:00:47
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-06 23:00:47
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Error writing request: fwrite(): SSL: Permission denied @ 2025-08-07 00:00:13
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-07 01:00:47
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-07 02:00:47
A communications error occurred while attempting to call XMLRPC method merge_installedpackages_section: Unable to connect to tls://172.16.71.3:443. Error: Operation timed out @ 2025-08-07 03:00:47
Communications error occurred
Exception calling XMLRPC method merge_installedpackages_section #-1 : Authentication failed: Invalid username or password @ 2025-08-07 00:00:04
Exception calling XMLRPC method merge_installedpackages_section #-1 : Authentication failed: Invalid username or password @ 2025-08-07 00:00:11
Exception calling XMLRPC method merge_installedpackages_section #-1 : Authentication failed: Invalid username or password @ 2025-08-07 00:00:12

I made sure to reenter the password to the second node and restarted PHP to no avail. What am I doing wrong?

[KKIT]

Update, here an output of the sockstat, 80 and 443 appear to be open.

[stephenw10]

Do you see blocked traffic on secondary?

It sure looks like it's failing to authenticate there. Are you using a complex password? Are you using the admin user for the xml sync?