Explanation
To configure CyberArk to use HTML5 gateways exclusively for PSM connections, you need to set the DefaultConnectionMethod to HTML5 in the PVWA. This is done by logging in to the PVWA with an administrative user, navigating to Options > Privileged Session Management UI, and setting the DefaultConnectionMethod to HTML51. This configuration ensures that HTML5 sessions are triggered only for PSM machines associated with the HTML5 Gateway1.
References:
* CyberArk Docs - Secure Access with an HTML5 Gateway1

Explanation
When a DR Vault Server becomes an active vault, it will automatically fail back to the original state once the Primary Vault comes back online, if the AllowFailback setting is set to "yes" in the padr.ini file. The padr.ini file is the configuration file for the Disaster Recovery application, which enables the DR Vault to replicate data from the Primary Vault and take over its role in case of a failure. The AllowFailback setting determines whether the DR Vault will automatically switch back to the passive mode when the Primary Vault is restored. The default value of this setting is "no", which means that the DR Vault will remain active until a manual failback is performed1. To enable the automatic failback, the setting must be changed to "yes" and the padr service must be restarted1. The dbparm.ini file is not relevant to this setting, as it is the main configuration file for the Vault database2. References:
* Configure the DR Vault - CyberArk, section "AllowFailback"
* DBParm.ini - CyberArk, section "Main parameters"