ssh/webapp unavailable when in BACKUP mode

[antd]

Hello,

We are running a dual Netgate 1537 with HA configured (pf1 as master and pf2 as backup).
Last week we updated from v23.3 to 24.11.

We first updated our backup PfSense2 and then switched our PfSense1, which is the master, to ‘Persistent CARP Maintenance Mode’. As soon as we entered “Persistent CARP Maintenance Mode” (and still in 23.3) we lost access to webgui/ssh but the system was still working fine.

We regained access to the pf1 trough th SYNC interface and updated the system to 24.11 as well. From now on, we cannot access the BACKUP system anymore (webgui/ssh), the MASTER is working fine. If we switch MASTER/BACKUP, we still can’t access the BACKUP one.

So, we ran a tcpdump and found that the packets arrived but were dropped.
In the firewall logs, we see that these packets are blocked by the default deny ipv4 rule (1000000103). But this shouldn't be the case because the firewall has a rule that authorises port 443 as well as 22.

We also forced a pkf reinstall on both pfsense (https://docs.netgate.com/pfsense/en/latest/troubleshooting/upgrades.html).

Any advice to fix the problem/bug ?

Thanks in advance,