Steps to reproduce:

• Create a host with PSK checkbox enabled and PSK properties set;
• Open Host edit form:
  • Observe the "Change PSK" button;
  • Unckeck "PSK" checkbox.
• Press "Clone" button;
• Check "PSK" checkbox again.

Result:

Form appears with empty "PSK identity" and "PSK" input fields. In Zabbix 5.4 there would be "Change PSK" button.

Repeating the same steps with Proxy, both Zabbix 6.0 and Zabbix 5.4 behaves same way - "Change PSK" button is displayed.