pfsync not working after update (Error 403)

[vaios]

Hello!

Yesterday, I upgraded OPNsense to version 25.4.1. Since then, pfsync is no longer working and I get the following error message:

/usr/local/etc/rc.filter_synchronize: An error occurred while attempting XMLRPC root with username sync and https://192.168.0.1/xmlrpc.php fetch error. remote host down? (CONNECT tunnel failed, response 403)

The backup firewall is not accessible (check user credentials).

I have already checked the password and it works. It seems like the primary firewall is not even trying to connect. When I check with tcpdump, no packets are being sent, even though the connection itself works.

Additionally, I noticed that when I try to change the user in the "System: High Availability: Settings" menu, the error message still shows the old username. It seems like the change is not being applied.

For example, running curl shows that the connection is fine:
curl https://192.168.0.1 -k -v
*   Trying 192.168.0.1:443...
> GET / HTTP/2
> Host: 192.168.0.1
> User-Agent: curl/8.13.0
> Accept: */*
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* TLSv1.3 (IN), TLS handshake, Newsession Ticket (4):
* Request completely sent off
< HTTP/2 200
< date: Tue, 22 Jul 2025 09:50:10 GMT
< server: OPNsense

Thank you for your help!