OpnSense Master - Slave problem

[dlomartire]

We have a problem with a pair of opensense (master/slave) which up until 10 days ago have always worked well and without problems. For 10 days, without any configuration changes, if the two opnsenses are both up, everything running behind the haproxy is no longer reachable so we decided to keep the slave off. By doing this, there are no more problems. The traffic on the HA (when the two opnsense are turned on) skyrockets beyond 20mb, 50 or even 300mb when it regularly did not exceed (before the problem) 1mb.
Has this happened to anyone? What can it be? I repeat, no changes have been made to the configurations.
Thank you