Steps to reproduce:

1. Keep zabbix server configuration, including HANodeName as is.
2. Upgrade HA node one, reboot
3. Upgrade HA node two, reboot
4. Observe HA node one is doing automatic db update, but stuck at 50%
5. Observe database host looks idle - almost no CPU load, almost no IO.
6. Observe HA node two server is stuck during shutdown - had to force a reset
7. Observe HA node two is doing automatic db update, but also stuck

It is a tiny HA cluster for testing (2 servers, 2 proxies, one postgres; 30 hosts, 23807 items, 12403 triggers, 41634 auditlog records), fresh install since 7.0alpha2 if I remember right.

It is first time I am reporting something like this, so I apologize in advance it is not complete